XYZ v Commonwealth

The case involved a plaintiff charged with offences under sections 50BA and 50BC of the Crimes Act 1914 (Cth), which prohibit engaging in sexual activity with a child under 16 years of age outside Australia. The plaintiff challenged the constitutional validity of these provisions, arguing they were not valid laws with respect to the external affairs power under section 51(xxix) of the Constitution. The matter came before the High Court of Australia by way of a Case Stated.

The High Court was required to determine whether sections 50BA and 50BC of the Crimes Act 1914 (Cth) constitute laws with respect to "external affairs" within the meaning of section 51(xxix) of the Constitution. This involved considering the scope of the external affairs power, specifically whether it extends to any place, person, matter, or thing outside Australia, or if it is restricted to subjects with a connection to Australia, matters touching Australia's relationships with other countries, or matters of international concern, particularly in the context of implementing treaty obligations. The Court also considered principles of constitutional interpretation, including the relevance of international law and the potential for legislative overreach.

The Court reasoned that the external affairs power is not confined to matters having a direct connection with Australia or its relationships with other nations. Instead, it encompasses the implementation of international law, including treaty obligations. The Court found that the impugned provisions were enacted to give effect to Australia's obligations under the Convention on the Rights of the Child and its Optional Protocol, which address the sexual exploitation of children. Consequently, the Court held that both sections 50BA and 50BC of the Crimes Act 1914 (Cth) are valid laws with respect to the external affairs power.

The questions set out in the Case Stated were answered as follows: Question 1, "Is either of sections 50BA and 50BC of the Crimes Act 1914 (Cth) a law 'with respect to ... External affairs' within section 51(xxix) of the Constitution?", was answered "Yes, both of them." As this question was answered in the affirmative, the second question did not arise. The costs of the Case Stated were ordered to be borne by the plaintiff.