High Court. Does the constitutionally permissible period of executive detention of an alien who has failed to obtain permission to remain in Australia come to an end when there is no real prospect of removal of the alien from Australia becoming practicable in the reasonably foreseeable future? If so, who bears the onus of proving that there is no real prospect of removal becoming practicable in the reasonably foreseeable future?
Some of the questions to the High Court (HCA) were as follows:
Question 1: Is leave required before the High Court to reopen a previous decision of the High Court?
Question 2: If the answer to Question 1 is 'yes', is the evaluation of such considerations as may bear on the appropriateness of granting leave to be "informed by a strongly conservative cautionary principle, adopted in the interests of continuity and consistency in the law, that such a course should not lightly be taken"?
Question 3: If the answer to Question 1 is 'yes', should it be granted?
Question 4: Can it be said that "a law enacted by the Commonwealth Parliament which authorises the detention of a person, other than through the exercise by a court of the judicial power of the Commonwealth in the performance of the function of adjudging and punishing criminal guilt, will contravene Ch III of the Constitution unless the law is reasonably capable of being seen to be necessary for a legitimate and non-punitive purpose"? In other words, is detention penal or punitive unless justified as otherwise?
Question 5: If the answer to Question 4 is 'yes', is that legitimate and non-punitive purpose that which the law is designed to achieve in fact?
Question 6: If the answer to Question 4 is 'yes', must that purpose be both legitimate and non-punitive?
Question 7: If the answer to Question 4 is 'yes', does the term "legitimate" refer to the need for the purpose said to justify detention to be compatible with the constitutionally prescribed system of government?
Question 8: If the answer to Question 4 is 'yes', can a legitimate and non‑punitive purpose of detention of an alien be properly identified as separation from the Australian community pending removal (if ever)?
Question 9: Does the constitutionally permissible period of executive detention of an alien who has failed to obtain permission to remain in Australia come to an end when there is no real prospect of removal of the alien from Australia becoming practicable in the reasonably foreseeable future? In other words, is immigration detention unlawful from the moment that removal from Australia is not practicable in the reasonably foreseeable future?
Question 10: If the answer to Question 9 is 'yes', did the plaintiff bear an initial evidential burden of establishing that there was reason to suppose that his detention had ceased to be lawful by reason that it transgressed the applicable constitutional limitation on his detention, with the defendants bearing the legal burden of proving that the constitutional limitation was not transgressed?
Question 11: If the answer to Question 10 is 'yes' and the plaintiff discharged that initial evidential burden, were the defendants required to prove that there existed a real prospect of his removal from Australia becoming practicable in the reasonably foreseeable future?
Question 12: If the answer to Question 10 is 'yes', can it be said that "whilst the proof was required to be to a standard sufficient to support the making of a finding of fact to the level of satisfaction appropriate in a civil proceeding where individual liberty is in issue, the prospective and probabilistic nature of the fact in issue (that is, the fact of a real prospect of the plaintiff's removal from Australia becoming practicable in the reasonably foreseeable future) would have the potential to be confused were the standard of proof to be "on the balance of probabilities""?
Question 13: Should release from unlawful detention be equated with a grant of a right to remain in Australia?
The HCA answered those questions as follows: