Muhammad Izwan bin Borhan v Public Prosecutor and another appeal [2025] SGCA 55

Sushant Shukla

Case Details

Citation: [2025] SGCA 55
Court: Court of Appeal of the Republic of Singapore
Decision Date: 3 December 2025
Coram: Sundaresh Menon CJ, Tay Yong Kwang JCA, Belinda Ang Saw Ean JCA
Case Number: Criminal Appeal No 11 of 2022; Criminal Appeal No 12 of 2022
Hearing Date(s): 10 July 2025
Appellants: Muhammad Izwan bin Borhan; Ahmad Suhaimi bin Ismail
Respondent: Public Prosecutor
Counsel for Appellants: Cheong Jun Ming Mervyn, Lim Yi Zheng (Advocatus Law LLP) and Chooi Jing Yen (Chooi Jing Yen LLC) for the first appellant; Vergis S Abraham, Loo Yinglin Bestlyn (Providence Law Asia LLC), Suang Wijaya and Jordan Kow (Eugene Thuraisingam LLP) for the second appellant
Counsel for Respondent: Kumaresan Gohulabalan and Stephanie Koh (Attorney-General’s Chambers)
Practice Areas: Criminal Law; Statutory offences; Misuse of Drugs Act

The Court of Appeal, in [2025] SGCA 55, dismissed the appeals of Muhammad Izwan bin Borhan (“Izwan”) and Ahmad Suhaimi bin Ismail (“Suhaimi”) against their convictions and mandatory death sentences for drug trafficking. The case centered on the trafficking of not less than 26.19g of diamorphine and not less than 252.04g of methamphetamine. The appellants were originally convicted in [2022] SGHC 40 (the “First Judgment”). Following the initial appeal, the matter was remitted to the High Court for a supplemental hearing to consider additional evidence, which resulted in the supplemental judgment [2025] SGHC 15 (the “Second Judgment”). The Court of Appeal’s final decision reaffirms the stringent standards required to challenge the chain of custody and the high threshold for rebutting statutory presumptions under the Misuse of Drugs Act.

The primary doctrinal contribution of this judgment lies in its detailed treatment of the "chain of custody" defense and the "reduced order" factual defense. The appellants argued that the quantity of drugs they intended to traffic was significantly lower than what was seized, claiming an eleventh-hour reduction in the order from five "biji" (packets) of heroin to one. Furthermore, they alleged a break in the chain of custody regarding the drug exhibits, specifically exhibit F1B1. The Court of Appeal meticulously examined the movement of the exhibits from the point of seizure at Toh Guan East to the Health Sciences Authority (HSA), concluding that the integrity of the evidence remained intact despite minor administrative discrepancies in the recording of gross weights.

The judgment also clarifies the application of abetment by conspiracy under section 107 of the Penal Code in the context of drug trafficking. Suhaimi, who was not physically present at the collection site, was found to have abetted Izwan’s trafficking through a common design. The court emphasized that it is not necessary for all co-conspirators to be equally informed of every detail of the operation, provided they are aware of the general purpose and the unlawful nature of the plot. This holding reinforces the liability of "coordinators" or "intermediaries" in drug syndicates who may not handle the physical substances but facilitate the trade.

Ultimately, the Court of Appeal found that the Prosecution had proven its case beyond reasonable doubt. The court rejected the appellants' attempts to characterize the methamphetamine as being held for personal use or as a mere bailee. The dismissal of the appeals underscores the judiciary's reliance on contemporaneous statements and objective evidence, such as call logs and text messages, over later-developed trial defenses that contradict earlier admissions. The decision serves as a definitive statement on the finality of factual findings made by a trial judge when supported by a robust evidentiary basis.

Timeline of Events

18 September 2017: Initial communications regarding drug transactions begin (referenced in factual matrix).
19 September 2017: Further coordination between the parties and the Malaysian supplier, "Arun".
24 September 2017: Continued planning of the drug collection.
27 September 2017: Finalization of the arrangements for the delivery of heroin and Ice.
29 September 2017 (11:38 am): Izwan leaves his residence to proceed to the collection point.
29 September 2017 (12:22 pm): Izwan arrives via taxi at Toh Guan East.
29 September 2017 (12:46 pm): At a location near 31 Toh Guan East, Izwan collects five “biji” of heroin and one packet of 500 grams of Ice from Arun’s runner.
29 September 2017 (Afternoon): Izwan returns home, repackages one “biji” of heroin, and is subsequently arrested by CNB officers.
30 September 2017: Recording of initial statements from the appellants.
2 October 2017: Further investigative statements taken by CNB.
3 October 2017: Continuation of the statement recording process.
4 October 2017: Detailed statements regarding the drug quantities and the role of "Arun" are recorded.
13 December 2017: Final investigative statements completed.
26 March 2020: Commencement of trial proceedings in the High Court.
6 April 2021: Trial continues with testimony from investigating officers and the appellants.
18 May 2021: Further trial dates for the cross-examination of the appellants.
19 May 2021: Conclusion of the initial trial evidence.
[2022] SGHC 40: The High Court delivers the First Judgment, convicting both appellants and sentencing them to death.
27 November 2024: Supplemental hearing in the High Court following remission by the Court of Appeal.
29 November 2024: Conclusion of the supplemental hearing.
[2025] SGHC 15: The High Court delivers the Second Judgment, maintaining the convictions.
10 July 2025: Substantive hearing of the appeals before the Court of Appeal.
3 December 2025: The Court of Appeal delivers the final judgment in [2025] SGCA 55.

What Were the Facts of This Case?

The case involves a sophisticated drug trafficking operation involving two Singaporean men, Muhammad Izwan bin Borhan (“Izwan”) and Ahmad Suhaimi bin Ismail (“Suhaimi”). Izwan, born in November 1985, and Suhaimi, born in May 1992, had a long-standing relationship dating back to 2008, which was further cemented when they reconnected in prison school in 2014. Both were involved with a drug dealer named Mohamed Yusof bin Kasim (“Yusof”), who facilitated connections with a Malaysian supplier known as “Arun”. The core of the criminal enterprise involved the importation and distribution of diamorphine (heroin) and methamphetamine (Ice) within Singapore.

On 29 September 2017, the operation culminated in a physical collection of drugs. Izwan left his residence at approximately 11:38 am and traveled by taxi to Toh Guan East, arriving at 12:22 pm. At approximately 12:46 pm, near 31 Toh Guan East, Izwan met with a runner sent by Arun. During this encounter, Izwan collected five “biji” (large packets) of heroin and one large packet containing approximately 500 grams of Ice. Following the collection, Izwan returned to his residence where he began the process of repackaging the drugs for further distribution. Specifically, he was found to have repackaged one “biji” of heroin into smaller sachets.

Central Narcotics Bureau (“CNB”) officers, who had been monitoring the situation, moved in to arrest Izwan at his residence. During the search, they seized various drug exhibits, including the five packets of heroin and the large packet of Ice. The forensic analysis conducted by the Health Sciences Authority later confirmed that the exhibits contained not less than 26.19g of diamorphine and not less than 252.04g of methamphetamine. These quantities significantly exceeded the capital punishment thresholds stipulated in the Misuse of Drugs Act.

The Prosecution’s case against Izwan was that he possessed these drugs for the purpose of trafficking. Against Suhaimi, the Prosecution alleged that he had abetted Izwan’s trafficking by coordinating the transaction with Arun. Suhaimi’s role was characterized as the intermediary who negotiated the prices and quantities with the Malaysian supplier and directed Izwan to the collection point. The evidence included extensive call logs and text messages between Suhaimi, Izwan, and Arun in the days leading up to the arrest, specifically from 18 September 2017 to 29 September 2017.

The appellants offered a different version of events at trial. They claimed that while an initial order for five “biji” of heroin had been placed, this order was reduced to only one “biji” just before the collection because they lacked the funds to pay for the full amount. They argued that Izwan had mistakenly collected the original, larger amount because the runner simply handed over the bag without checking. Regarding the Ice, Suhaimi claimed it was intended for his own personal consumption or that Izwan was merely holding it as a bailee for him, without any intention to traffic it. They further challenged the integrity of the drug exhibits, alleging that the CNB officers had mishandled the evidence, specifically exhibit F1B1, leading to a break in the chain of custody.

The procedural history of the case is notable for its complexity. After the initial conviction in [2022] SGHC 40, the Court of Appeal remitted the case for a supplemental hearing to investigate the handling of the exhibits by ASP Bong, the primary investigating officer. This resulted in the Second Judgment in [2025] SGHC 15, where the trial judge maintained the original findings of guilt after hearing further testimony from ASP Bong and other CNB officers. The appellants’ defense was largely predicated on the assertion that the discrepancies in the recorded weights of the drugs suggested tampering or loss of evidence, an argument the trial judge and subsequently the Court of Appeal rejected.

What Were the Key Legal Issues?

The appeals raised several critical legal issues concerning the standards of proof in capital drug cases and the procedural requirements for maintaining the integrity of evidence. The court was required to determine whether the trial judge had erred in his assessment of the facts and the application of the law.

Chain of Custody: Whether the Prosecution had established a continuous and unbroken chain of custody for the drug exhibits, particularly exhibit F1B1. This involved analyzing whether the discrepancies in the "gross weight" recorded by the investigating officer versus the "net weight" recorded by the HSA laboratory indicated a breach of integrity.
The "Reduced Order" Defense: Whether there was a reasonable doubt that the appellants only intended to traffic one "biji" of heroin instead of the five "biji" found in Izwan's possession. This required a deep dive into the contemporaneous communications and the credibility of the appellants' trial testimony.
Abetment by Conspiracy: Whether Suhaimi’s involvement met the criteria for abetment under section 107 of the Penal Code. The issue was whether Suhaimi and Izwan shared a common design to traffic the specific quantities of diamorphine and methamphetamine charged.
Statutory Presumptions: The application of the s 17(c) presumption of the Misuse of Drugs Act, which presumes possession for the purpose of trafficking based on the quantity of drugs held. The court had to decide if Izwan had successfully rebutted this presumption on a balance of probabilities.
Admissibility and Weight of Statements: The extent to which the court should rely on the appellants' investigative statements, which contained admissions, versus their trial testimony, which sought to distance them from the full scope of the charges.

How Did the Court Analyse the Issues?

The Court of Appeal’s analysis was exhaustive, spanning 93 pages and addressing every facet of the appellants' challenges. The judgment, delivered by Tay Yong Kwang JCA, began by addressing the chain of custody, which is often a primary battleground in drug trafficking appeals. The appellants relied on the decision in Lim Swee Seng v Public Prosecutor [1995] 1 SLR(R) 32 to argue that the discrepancies in the recorded weights of the exhibits were fatal to the Prosecution's case. However, the court distinguished Lim Swee Seng, noting that in that case, the gross weight of the drugs was less than the weight of the drugs alone when later measured, which was physically impossible. In the present case, the court found that the discrepancies were administrative in nature and did not suggest tampering. The court held that the "gross weight" recorded by the investigating officer (ASP Bong) was an approximation used for internal tracking and did not undermine the precise "net weight" analysis conducted by the HSA.

Regarding the "reduced order" defense, the court conducted a granular review of the communications between the appellants and the supplier, Arun. The appellants claimed that a phone call made shortly before the collection served to reduce the order from five "biji" to one. The court rejected this, pointing out that the call logs showed no such conversation that would support a reduction in quantity. Furthermore, Izwan’s own actions—collecting the bag containing five "biji" and immediately beginning to repackage them upon returning home—were entirely inconsistent with the claim of a mistaken collection. The court noted at [123] that Izwan is presumed under ss 17(c) of the Misuse of Drugs Act to possess the heroin for the purpose of trafficking, and his explanation failed to meet the "balance of probabilities" threshold required to rebut that presumption.

The analysis of Suhaimi’s liability for abetment was grounded in section 107 of the Penal Code. The court cited [2012] SGCA 18 at [33], emphasizing that abetment by conspiracy requires an agreement to do an unlawful act. The court found that Suhaimi was the "mastermind" or at least the primary coordinator of the transaction. The evidence showed that Suhaimi had negotiated the price of $2,850 per "biji" and had arranged for the delivery of the 500g of Ice. The court rejected Suhaimi’s claim that the Ice was for personal use, noting that the quantity (252.04g of pure methamphetamine) was vastly in excess of what any individual would consume, even a heavy user. The court applied the reasoning in Ali bin Mohamad Bahashwan v Public Prosecutor and other appeals [2018] 1 SLR 610, stating that it is not necessary for all co-conspirators to be equally informed of every detail, as long as they know the general nature of the drugs and the unlawful purpose.

The court also addressed the supplemental evidence from the remitted hearing. The appellants had argued that ASP Bong’s testimony was unreliable because he had initially failed to disclose certain movements of the drug exhibits. The court, however, agreed with the trial judge’s assessment in the Second Judgment ([2025] SGHC 15). While acknowledging that ASP Bong’s record-keeping was not perfect, the court found no evidence of bad faith or tampering. The court cited [2022] SGHC 5 at [48], noting that even if a witness is impeached on certain points, the court can still accept other parts of their testimony if they are corroborated by objective facts. The court concluded that the chain of custody remained "secure and unbroken" from the time of seizure at Toh Guan East to the delivery to the HSA.

Finally, the court dealt with the knowledge of the drug nature. Izwan argued that he did not know the exact quantity or nature of the drugs in the bag. The court referred to Arun Ramesh Kumar v Public Prosecutor [2022] 1 SLR 1152 at [28], which establishes that the test for knowledge is what the accused actually knew or believed. Given Izwan’s history as a drug dealer and his specific instructions from Suhaimi and Arun, the court found it "incredible" that he would not have known he was collecting a large quantity of heroin and Ice. The court held that the Prosecution had successfully invoked the presumptions and that the appellants had failed to provide any credible evidence to the contrary.

"We agree with the Judge’s finding that the respective charges against Izwan and Suhaimi were established beyond reasonable doubt." (at [186])

What Was the Outcome?

The Court of Appeal dismissed both appeals in their entirety. The convictions of Muhammad Izwan bin Borhan and Ahmad Suhaimi bin Ismail for trafficking in diamorphine and methamphetamine were upheld. Consequently, the mandatory death sentences imposed by the High Court were affirmed. The court found no merit in the arguments regarding the chain of custody, the reduction of the drug order, or the lack of knowledge regarding the nature of the substances.

The court’s final orders were as follows:

The appeal by Izwan in CA/CCA 11/2022 against conviction and sentence was dismissed.
The appeal by Suhaimi in CA/CCA 12/2022 against conviction and sentence was dismissed.
The findings of the trial judge in both the First Judgment ([2022] SGHC 40) and the Second Judgment ([2025] SGHC 15) were fully endorsed.

The court emphasized that the evidence against the appellants was "overwhelming." The combination of contemporaneous telecommunication records, the physical seizure of the drugs in Izwan's possession, and the admissions made in their early investigative statements formed a cohesive and irrefutable case for the Prosecution. The court specifically noted that the appellants' trial defenses were "afterthoughts" designed to avoid the capital consequences of their actions.

"Accordingly, we dismiss both Izwan’s and Suhaimi’s appeals against their conviction and sentence." (at [188])

There were no orders as to costs, as is standard in criminal appeals of this nature in Singapore. The judgment marks the end of the legal process for the appellants, affirming the state's application of the mandatory death penalty for high-volume drug trafficking offenses. The court's refusal to interfere with the trial judge's assessment of witness credibility—particularly regarding the CNB officers and the appellants themselves—highlights the limited scope for appellate intervention in fact-heavy criminal cases.

Why Does This Case Matter?

This judgment is a significant addition to Singapore’s criminal jurisprudence, particularly in the realm of capital drug offenses. It reinforces several key principles that practitioners must navigate when handling such cases. First, it clarifies the threshold for challenging the chain of custody. The court made it clear that minor administrative discrepancies or imperfect record-keeping by investigating officers do not automatically result in an acquittal. For a chain of custody defense to succeed, there must be a "real possibility" of tampering or loss of integrity that creates reasonable doubt. By distinguishing Lim Swee Seng, the court has narrowed the window for technical challenges based on weight discrepancies, emphasizing that the focus should be on the actual security of the exhibits.

Second, the case illustrates the robustness of the abetment by conspiracy doctrine. The conviction of Suhaimi, who was not at the scene of the crime, demonstrates that the law effectively reaches those who orchestrate drug transactions from behind the scenes. The court’s reliance on [2012] SGCA 18 and Ali bin Mohamad Bahashwan confirms that a "common design" can be inferred from the totality of the circumstances, including prior coordination and financial arrangements. This is a vital tool for the Prosecution in dismantling drug distribution networks where roles are specialized and decentralized.

Third, the judgment serves as a warning regarding the weight of contemporaneous statements. The Court of Appeal repeatedly contrasted the appellants' trial testimony with their initial statements to the CNB. The court’s preference for the latter—recorded closer to the time of the offence and before the appellants had the opportunity to consult with counsel or refine their defenses—highlights the difficulty of successfully raising "afterthought" defenses in the Singapore courts. Practitioners must be aware that any deviation from early statements will be viewed with extreme skepticism unless there is a compelling explanation (such as coercion, which was not proven here).

Fourth, the remission for a supplemental hearing ([2025] SGHC 15) shows the court's commitment to procedural fairness, even in the face of strong evidence. By allowing the appellants to cross-examine the investigating officer on the handling of the exhibits, the court ensured that the death penalty was not affirmed without a thorough investigation into potential procedural lapses. However, the ultimate dismissal of the appeals after this process suggests that such supplemental hearings will only lead to a different outcome if they uncover substantial and material errors that go to the heart of the conviction.

Finally, the case reinforces the strict application of the Misuse of Drugs Act presumptions. The failure of the appellants to rebut the s 17(c) presumption on a balance of probabilities underscores the heavy burden placed on the defense once possession of a threshold quantity is established. The court’s rejection of the "bailee" and "personal use" defenses for the 500g of Ice reflects a pragmatic approach to the realities of the drug trade, where such large quantities are almost invariably intended for commercial distribution.

Practice Pointers

Chain of Custody Challenges: Practitioners should focus on discrepancies that are "physically impossible" or suggest actual tampering rather than mere administrative errors in "gross weight" recording. The HSA's net weight analysis remains the gold standard for the court.
Contemporaneous Statements: Advise clients that early investigative statements are given significant weight. Any subsequent trial testimony that contradicts these statements will likely be treated as an "afterthought" and require a very high level of corroboration to be believed.
Abetment Liability: In conspiracy cases, emphasize that the Prosecution does not need to prove the accused knew every detail of the transaction. Evidence of coordination, price negotiation, and directing others to collection points is sufficient to establish a common design.
Rebutting Presumptions: To rebut the s 17(c) presumption of trafficking, the defense must provide a version of events that is more probable than not. Vague claims of "mistaken collection" or "reduction of order" are unlikely to succeed without supporting objective evidence like call logs or text messages.
Supplemental Evidence Strategy: While remissions for supplemental hearings are rare, they provide a critical opportunity to probe procedural lapses. However, practitioners should be prepared for the fact that unless the new evidence fundamentally undermines the Prosecution's core case, the original conviction is likely to stand.
Personal Use Defenses: Claims of personal consumption for large quantities of drugs (e.g., 250g+ of pure methamphetamine) are viewed with extreme skepticism. Such defenses require detailed evidence of the accused's consumption habits and financial ability to sustain such a habit.

Subsequent Treatment

As a very recent decision from the Court of Appeal delivered in December 2025, [2025] SGCA 55 stands as a leading authority on the interplay between investigating officer testimony and the integrity of drug exhibits. It is expected to be frequently cited in future drug trafficking appeals where the chain of custody is in issue, particularly for its clarification that administrative discrepancies in gross weight do not necessarily constitute a break in the chain. The judgment also solidifies the application of abetment principles in multi-party drug transactions.