Thoms v The Commonwealth

The High Court of Australia considered a question concerning the lawfulness of the detention of Brendan Craig Thoms. The dispute arose because Mr. Thoms was detained as an "unlawful non-citizen" under section 189(1) of the *Migration Act 1958* (Cth) based on the reasonable suspicion of immigration officers that he did not hold a valid visa and was not an Australian citizen. This detention continued until the High Court's decision in *Love v The Commonwealth* (2020) 270 CLR 152, which determined that Mr. Thoms was not an "alien" for the purposes of section 51(xix) of the Constitution.

The legal issues before the Court were whether Mr. Thoms' detention between 28 September 2018 and 11 February 2020 was lawful under section 189(1) of the *Migration Act*, and whether section 51(xix) of the Constitution supported the valid application of section 189(1) to Mr. Thoms during that period. The Court was required to reconcile the operation of the *Migration Act*, which treats "non-citizens" as synonymous with "aliens" for the purposes of its constitutional foundation in the aliens power, with the subsequent determination in *Love* that Mr. Thoms was not an alien.

The Court reasoned that the *Migration Act* has been enacted and administered on the premise that the Parliament's power under section 51(xix) of the Constitution to make laws with respect to "aliens" supports the Act's provisions concerning "unlawful non-citizens". The Court noted that since 1984, the Commonwealth Parliament has relied on the aliens power to sustain the *Migration Act*, and the term "non-citizen" within the Act has been understood as synonymous with "alien". Crucially, the Court held that the detention of Mr. Thoms was lawful at the time it occurred because the detaining officers held a reasonable suspicion that he was an unlawful non-citizen, and this suspicion was sufficient to engage section 189(1) of the *Migration Act*. The subsequent finding in *Love* that Mr. Thoms was not an alien did not render his prior detention unlawful, as the lawfulness of detention is assessed based on the circumstances and the law as it stood at the time of detention.

The Court answered the separate question removed into the Court by stating: "No." This signifies that the detention of Brendan Craig Thoms between 28 September 2018 and 11 February 2020 was not unlawful. No question as to costs arose.