A. AND OTHERS v. THE UNITED KINGDOM JUDGMENT 81 trial, the rights of the defence would be restricted to an extent incompatible with the guarantees provided by Article 6. 208. Similarly, in Doorson (cited above, §§ 68-76), the Court found that there was no breach of Article 6 where the identity of certain witnesses was concealed from the defendant, on the ground that they feared reprisals. The fact that the defence counsel, in the absence of the defendant, was able to put questions to the anonymous witnesses at the appeal stage and to attempt to cast doubt on their reliability and that the Court of Appeal stated in its judgment that it had treated the evidence of the anonymous witnesses with caution was sufficient to counterbalance the disadvantage caused to the defence. The Court emphasised that a conviction should not be based either solely or to a decisive extent on anonymous statements (see also Van Mechelen and Others, cited above, § 55). In each case, the Court emphasised that its role was to ascertain whether the proceedings as a whole, including the way in which evidence was taken, were fair (see Doorson, cited above, § 67). 209. The Court has referred on several occasions to the possibility of using special advocates to counterbalance procedural unfairness caused by lack of full disclosure in national security cases, but it has never been required to decide whether or not such a procedure would be compatible with either Article 5 § 4 or Article 6 of the Convention. 210. In Chahal (cited above), the applicant was detained under Article 5 § 1 (f) pending deportation on national security grounds and the Secretary of State opposed his applications for bail and habeas corpus, also for reasons of national security. The Court recognised (ibid., §§ 130-31) that the use of confidential material might be unavoidable where national security was at stake but held that this did not mean that the executive could be free from effective control by the domestic courts whenever they chose to assert that national security and terrorism were involved. The Court found a violation of Article 5 § 4 in the light of the fact that the High Court, which determined the habeas corpus application, did not have access to the full material on which the Secretary of State had based his decision. Although there was the safeguard of an advisory panel, chaired by a Court of Appeal judge, which had full sight of the national security evidence, the Court held that the panel could not be considered as a “court” within the meaning of Article 5 § 4 because the applicant was not entitled to legal representation before it and was given only an outline of the national security case against him and because the panel had no power of decision and its advice to the Home Secretary was not binding and was not disclosed. The Court made reference (ibid., §§ 131 and 144) to the submissions of the third parties (Amnesty International, Liberty, the Centre for Advice on Individual Rights in Europe and the Joint Council for the Welfare of Immigrants; and see the submissions of Justice in the present case, paragraph 198 above) in connection with a procedure applied in national security deportation cases in