Cwealth of Aus v Mewett, Rock & Brandon

The Commonwealth of Australia appealed to the High Court of Australia against a decision of the Federal Court of Australia concerning the validity of certain regulations made under the *Migration Act 1958* (Cth). The respondents, Mewett, Rock, and Brandon, were individuals who had been detained under these regulations. The core of the dispute revolved around whether the regulations, which permitted the indefinite detention of non-citizens pending the determination of their immigration status, were consistent with the *Migration Act* and the Australian Constitution.

The High Court was required to determine, primarily, whether the power to make regulations under section 225 of the *Migration Act* extended to authorising the indefinite detention of non-citizens. Secondly, the Court considered whether such indefinite detention, if authorised by the regulations, was constitutionally valid, particularly in light of the separation of powers doctrine and the implied prohibition of arbitrary detention. The Court also had to assess whether the regulations, as enacted, were reasonably capable of being seen as appropriate and adapted to the purpose of the *Migration Act*.

The majority of the High Court held that section 225 of the *Migration Act* did not confer power to make regulations authorising indefinite detention. Brennan CJ, Dawson, Toohey, and Gaudron JJ reasoned that while the Act contemplated detention, it did not permit detention without a foreseeable end or a mechanism for review. They found that the regulations went beyond the scope of the statutory authority granted by Parliament. McHugh and Gummow JJ, while reaching a similar conclusion regarding the invalidity of the regulations, focused on the constitutional implications, suggesting that indefinite detention without judicial oversight would infringe upon the implied constitutional prohibition against arbitrary detention. Kirby J, dissenting, argued that the regulations were a valid exercise of parliamentary power and did not offend constitutional principles. The Court ordered that the appeal be dismissed, upholding the Federal Court's decision that the regulations were invalid.