The constitutional landscape of drug trafficking law in Malaysia has been substantially reshaped over the last fifteen years. Two Federal Court decisions stand at the centre: Public Prosecutor v Yong Vui Kong [2010] 5 MLJ 145 (Singapore Court of Appeal, persuasive in Malaysia) and Alma Nudo Atenza v Public Prosecutor [2019] 4 CLJ 567 (Malaysian Federal Court, binding). Together, these cases moved the death-penalty regime under section 39B of the Dangerous Drugs Act 1952 from a strict, presumption-heavy framework to one with constitutional safeguards and (after 2023) judicial discretion in sentencing.

PP v Yong Vui Kong — the Singapore decision that shaped Malaysian thinking

Yong Vui Kong was a 19-year-old Malaysian convicted of trafficking 47 grams of heroin in Singapore. He was sentenced to the mandatory death penalty under Singapore’s Misuse of Drugs Act. The Singapore Court of Appeal held that the mandatory death penalty for drug trafficking did not contravene Article 9 (right to life) of the Singapore Constitution. The decision drew global attention to the human-rights dimension of drug trafficking sentencing in Southeast Asia and significantly influenced subsequent Malaysian legal scholarship.

The constitutional arguments in Yong Vui Kong — disproportionate punishment, lack of judicial discretion, lack of differentiation between principal traffickers and mules — were the same arguments later raised before the Malaysian Federal Court in Alma Nudo and that ultimately influenced the Abolition of Mandatory Death Penalty Act 2023.

Alma Nudo Atenza — the binding Malaysian authority

The constitutional challenge succeeded in Malaysia in Alma Nudo Atenza v PP [2019] 4 CLJ 567. The Federal Court (9-judge bench) held that the operation of double presumptions — section 37(d) (possession) followed by section 37(da) (trafficking) — violated Article 5(1) (right to life and personal liberty) of the Federal Constitution. The court did not strike down section 37(da) entirely; instead, it held that the prosecution cannot rely on both presumptions cumulatively. Either possession or trafficking must be proved without reliance on the parallel presumption.

What this means for accused persons today

Three practical consequences:

1. Possession must be proved independently. The prosecution cannot start from constructive possession (s.37(d)) and chain it into trafficking presumption (s.37(da)). They must independently prove either knowing possession with reasonable certainty, or trafficking, before any presumption operates.
2. Mens rea is back in the analysis. The accused’s knowledge — did they know there were drugs in the parcel/bag/vehicle — must be proved or fairly inferred from circumstances, not presumed away.
3. Sentencing discretion exists. After the 2023 Abolition of Mandatory Death Penalty Act, the trial court can choose between the death penalty and life imprisonment + whipping. Mitigation matters: age, role in the trafficking chain, cooperation, personal circumstances, time on remand.

The constitutional argument as a defence tool

Defence counsel can now use the Alma Nudo principle in three ways:

• At trial — attacking the prosecution’s chain of presumption-based reasoning
• At appeal — challenging convictions secured pre-Alma Nudo where double-presumption reasoning was used
• At sentencing — marshalling Alma Nudo’s constitutional reasoning together with the 2023 Act to argue against the death penalty

Practical takeaway for prospective accused or families

If you or a family member has been charged under section 39B of the Dangerous Drugs Act 1952, the case is no longer a foregone conclusion. The Alma Nudo principle, the 2023 Act, and decades of constitutional jurisprudence give defence counsel real tools. Prompt instruction is critical — the time to challenge presumption-based reasoning is at the close of the prosecution case, not at appeal.

See also: Drug Trafficking Defence under the DDA 1952 | Criminal Defence Lawyer in Malaysia | Criminal Lawyer in Johor Bahru

About the author

Dr Chee Hui Bing is a Malaysian Advocate & Solicitor and former medical doctor. Principal of 克里斯和伙伴律师事务所, Batu Pahat, Johor. The firm conducts criminal defence work across Johor and on referral throughout Malaysia. Read full profile.