9.11.2017 A & Ors v Secretary of State for the Home Department [2004] EWCA Civ 1123 (11 August 2004) 29. The test to be applied by the Secretary of State in deciding whether to issue a certificate is that provided in Section 21(1) of the 2001 Act. 30. The subsection requires that the Secretary of State has a belief (21(1)(a)), and a suspicion (21(1)(b)). A reasonable belief can exist only on the basis of information received and the existence of a reasonable suspicion depends on an assessment of that information. A reasonable belief may be held on the basis of the receipt of information which has not been proved in the ordinary sense of that word. Suspicion may reasonably arise from unproved facts. 31. This court must make an assessment of whether the criteria in Section 21(1) were in the circumstances satisfied. While the approach adopted by the Commission can be expected to be a helpful guide, this court must form its own judgment and not merely review the manner in which the Commission made an assessment. 32. In O'Hara v Chief Constable of the Royal Ulster Constabulary [1997] AC 286, the House of Lords considered legislation under which a constable could arrest without warrant a person whom he had reasonable grounds of suspecting to be, amongst other things, a person who was concerned in the commission, preparation or instigation of certain acts of terrorism. That test required reasonable grounds for suspicion but not the reasonable belief also required by the present test. As to reasonable suspicion, Lord Hope of Craighead stated, at page 297G and following: "It is now commonplace for Parliament to enable powers which may interfere with the liberty of the person to be exercised without warrant where the person who exercises these powers has reasonable ground for suspecting that the person against whom they are to be exercised has committed or is committing an offence. The protection of the subject lies in the nature of the test which has to be applied in order to determine whether the requirement that there be reasonable grounds for the suspicion is satisfied. My Lords, the test which section 12(1) of the Act of 1984 has laid down is a simple but practical one. It relates entirely to what is in the mind of the arresting officer when the power is exercised. In part it is a subjective test, because he must have formed a genuine suspicion in his own mind that the person has been concerned in acts of terrorism. In part also it is an objective one, because there must also be reasonable grounds for the suspicion which he has formed. But the application of the objective test does not require the court to look beyond what was in the mind of the arresting officer. It is the grounds which were in his mind at the time which must be found to be reasonable grounds for the suspicion which he has formed. All that the objective test requires is that these grounds be examined objectively and that they be judged at the time when the power was exercised. …The information acted on by the arresting officer need not be based on his own observations, as he is entitled to form a suspicion based on what he has been told. His reasonable suspicion may be based on information which has been given to him anonymously or it may be based on information, perhaps in the course of an emergency, which turns out later to be wrong. As it is the information which is in his mind alone which is relevant however, it is not necessary to go on to prove what was known to his informant or that any facts on which he based his suspicion were in fact true. The question whether it provided reasonable grounds for the suspicion depends on the source of his information and its context, seen in the light of the whole surrounding circumstances." 33. In Rehman, the issue was as to when the Secretary of State could make a deportation order under Section 3(5)(b) of the Immigration Act 1971 on the ground that it would be conducive to the public good in the interests of national security. Lord Slynn of Hadley stated, at paragraph 22: "22. Here the liberty of the person and the opportunity of his family to remain in this country is at stake, and when specific acts which have already occurred are relied on, fairness requires that they should be proved to the civil standard of proof. But that is not the whole exercise. The Secretary of State, in deciding whether it is conducive to the public good that a person should be deported, is entitled to have regard to all the information in his possession about the actual and potential activities and the connections http://www.bailii.org/ew/cases/EWCA/Civ/2004/1123.html 9/113