High Court. Can it be said that a non‑citizen who does not have a visa that is in effect is not liable to detention under s 189(1) of the Migration Act 1958 (Cth) if they are not an alien? Can it be said that, "what constitutes reasonable grounds for suspecting a person to be an unlawful non‑citizen must be judged against what was known or reasonably capable of being known at the relevant time"? In other words, can it be said that what constitutes reasonable grounds cannot be invalid ab initio?
Some of the questions to the High Court (HCA) were as follows:
Question 1: Is the term "non‑citizen" as used in the Migration Act 1958 (Cth) synonymous with "alien", as the latter term is used in the Constitution?
Question 2: Can it be said that a non‑citizen who does not have a visa that is in effect is not liable to detention under s 189(1) if they are not an alien?
Question 3: Should the Court reject "any distinction between a mistake of law and one of fact as being relevant to the question of whether the suspicion that a person is an unlawful non‑citizen is reasonable in the circumstances"?
Question 4: Can it be said that, "what constitutes reasonable grounds for suspecting a person to be an unlawful non‑citizen must be judged against what was known or reasonably capable of being known at the relevant time"? In other words, can it be said that what constitutes reasonable grounds cannot be invalid ab initio?
The HCA answered those questions as follows: