Heijne v State of Western Australia

Heijne v State of Western Australia concerned an appeal to the High Court of Australia from a decision of the Supreme Court of Western Australia. The appellant, Mr Heijne, had been convicted of an offence under the *Environmental Protection Act 1986* (WA). The dispute centred on the interpretation of a provision within that Act which imposed a duty on the occupier of any land to take all reasonable and practicable measures to prevent the escape of controlled substances from that land. Mr Heijne argued that the provision imposed a strict liability offence, meaning that the prosecution did not need to prove any fault on his part.

The High Court was required to determine whether the offence created by section 112(1) of the *Environmental Protection Act 1986* (WA) was one of strict liability or required proof of fault on the part of the accused. Specifically, the Court had to consider whether the phrase "all reasonable and practicable measures" indicated an intention by the legislature to impose strict liability, or if it implied a requirement for the prosecution to prove a failure to take such measures.

Gummow and Bell JJ, in their joint judgment, held that the offence was not one of strict liability. Their Honours reasoned that the inclusion of the words "reasonable and practicable" indicated that the legislature intended to impose a standard of conduct that was objectively assessed. This meant that the prosecution would need to prove that the measures taken, or not taken, by the occupier fell short of what was reasonable and practicable in the circumstances. The Court drew upon established principles of statutory interpretation, noting that offences are generally presumed to require proof of mens rea unless the language of the statute clearly indicates otherwise, or the subject matter points to strict liability. The Court found that the language used in section 112(1) did not displace this presumption.

The appeal was allowed, and the conviction was quashed.