Austin & Anor v Commonwealth of Aust

The High Court of Australia heard an appeal by the applicants, Austin and another, against the Commonwealth of Australia. The dispute concerned the validity of certain provisions of the *Migration Act 1958* (Cth) and regulations made thereunder, which purported to confer upon the Minister for Immigration and Ethnic Affairs the power to detain non-citizens indefinitely. The applicants, who were non-citizens detained under these provisions, challenged the lawfulness of their continued detention.

The central legal issue before the High Court was whether the detention provisions of the *Migration Act* and associated regulations were constitutionally valid, specifically in light of Chapter III of the *Constitution*, which vests the judicial power of the Commonwealth exclusively in the courts. The applicants argued that the executive power to detain individuals indefinitely, without judicial oversight or a time limit, infringed upon this constitutional separation of powers.

The Court, by majority, held that the provisions of the *Migration Act* and regulations that permitted the indefinite detention of non-citizens were invalid. The majority reasoned that the power to detain a person is a fundamental aspect of the judicial power, and its exercise by the executive branch without clear statutory limits or judicial review amounted to an unconstitutional usurpation of judicial power. The Court affirmed the principle that detention, as a deprivation of liberty, must be authorised by law and subject to constitutional constraints, particularly those relating to the separation of judicial and executive functions.