Plaintiff S297/2013 v Minister for Immigration and Border Protection & Anor; Plaintiff M150 of 2013 by his Litigation Guardian Sister Brigid Marie Arthur v Minister for Immigration and Border Protection & Anor;...

These proceedings concerned two separate applications for judicial review heard together, brought by asylum seekers who had arrived in Australia by boat and were detained in offshore processing centres. The first applicant, Plaintiff S297/2013, was a minor who arrived in Australia in 2013 and was subsequently transferred to Nauru. The second applicant, Plaintiff M150 of 2013, was also a minor who arrived in Australia in 2013 and was transferred to Manus Island. Both applicants sought to challenge the lawfulness of their detention and the validity of decisions made concerning their immigration status. The applications were heard by Gageler J of the High Court of Australia.

The central legal issue before the Court was whether the detention of the applicants in offshore processing centres, and the associated conditions and circumstances, were authorised by Australian law. Specifically, the Court was required to determine whether the Minister for Immigration and Border Protection had the legal power to detain non-citizens in offshore processing centres outside of Australia, and whether such detention was consistent with the constitutional framework and relevant legislative provisions, particularly concerning the protection of minors. The applicants argued that their detention was unlawful and breached fundamental rights.

Gageler J's reasoning focused on the interpretation of the *Migration Act 1958* (Cth) and the constitutional limits on executive power. His Honour considered the scope of the Minister's powers to detain non-citizens, particularly in circumstances where those non-citizens were not physically within Australia. The judgment analysed the concept of "detention" in the context of international law and the constitutional requirement for lawful detention. Gageler J concluded that the executive government did not have the constitutional or statutory power to detain non-citizens in offshore processing centres in the circumstances presented, finding that the detention was not authorised by the *Migration Act* and was therefore unlawful.

The Court ordered that the detention of the applicants was unlawful.