Momcilovic v The Queen

The High Court of Australia considered an appeal by Mr Momcilovic against his conviction for trafficking in a commercial quantity of methylamphetamine. The central dispute concerned the constitutional validity of a statutory presumption contained within the *Drugs, Poisons and Controlled Substances Act 1981* (Vic). This presumption, s 5(1) of the *Drugs, Poisons and Controlled Substances Act 1981* (Vic), deemed that a person found in possession of a quantity of methylamphetamine exceeding 300 grams was trafficking in that substance, unless they could prove otherwise.

The primary legal issue before the High Court was whether this reverse onus provision, which required the accused to disprove the element of trafficking, infringed upon the implied constitutional prohibition against the legislative impairment of the judicial power of the Commonwealth. Specifically, the Court had to determine if the presumption impermissibly encroached upon the traditional role of the courts in determining guilt or innocence by requiring an accused to prove a fact that would otherwise be an element of the offence. A further issue was whether the presumption was consistent with the presumption of innocence, a fundamental common law principle.

The majority of the High Court held that the statutory presumption in s 5(1) of the *Drugs, Poisons and Controlled Substances Act 1981* (Vic) was invalid. The Court reasoned that the presumption, by requiring the accused to prove they were not trafficking, effectively shifted the burden of proof for a core element of the offence from the prosecution to the defence. This was found to be an impermissible intrusion into the judicial function, as it undermined the fundamental principle that an accused is presumed innocent until proven guilty beyond reasonable doubt. The Court distinguished this provision from other statutory presumptions that might relate to ancillary matters or require proof of facts that do not go to the core elements of an offence.

Consequently, the High Court allowed the appeal, quashed the conviction, and remitted the matter to the Supreme Court of Victoria for a retrial.