with the first element required to restrict the right to personal liberty by means of a precautionary measure, which is that it should indicate the existence of sufficient evidence about participation in the illegal act investigated (supra para. 311.b). The list of evidence gathered and the statement that the background information and “the preliminary statements of Víctor Manuel Ancalaf Llaupe” constitute “well-founded presumptions to consider that he had participated as a perpetrator of the three offenses” investigated (supra para. 314), does not allow it to be verified that this requirement had been met. It should be recalled that Mr. Ancalaf Llaupe was unable to examine the case file until June 2003, months after the conclusion of the preliminary proceedings, which had been kept confidential under article 78 of the Code of Criminal Procedure (supra paras. 138 to 140). It was only at the stage of the plenary proceedings that he could have access to the case file; however, he remained without access to the confidential files (supra paras. 142 to 144). 319. The European Court of Human Rights, when ruling on a detention in a case related to the investigation of a terrorist offense, stated that a situation is possible in which a suspect may be arrested “on the basis of information which is reliable but which cannot be disclosed to the suspect or produced in court without jeopardizing the informant.” The European Court decided that even though, owing to the difficulties inherent in the investigation and processing of terrorist crimes, the “reasonableness” cannot always be evaluated using the same standards as in ordinary crime, “the exigencies of dealing with a terrorist crime cannot justify stretching the notion of ‘reasonableness’ to the point where the safeguard secured by Article 5 § 1 (c) [of the European Convention] is impaired.”340 320. In the instant case, there is no evidence that the secrecy of everything relating to the preliminary proceedings (or the “confidential files” even after this) responded to a measure that was necessary in order to protect information that could affect the investigation. Consequently, the accused’s defense was not given the opportunity to examine any of the documents and evidence on which his deprivation of liberty was based. In addition, the investigating judge’s assertion in the indictment that there were “well-founded presumptions to consider that [Mr. Ancalaf] participated as perpetrator of the three offenses” investigated, was not accompanied by specific information that the accused and his defense could contest.341 Consequently, the Court decides that the State did not comply with the requirement of establishing the existence of sufficient evidence that would allow a reasonably presumption of the identity of those who had taken part in the offense investigated (supra para. 312.b). 321. Furthermore, the pre-trial detention de Víctor Ancalaf Llaupe was not ordered to achieve a legitimate objective, because the indictment did not refer to the need for deprivation of liberty 340 ECHR, Case of O’Hara v. The United Kingdom, No. 37555/97. Judgment of 16 October 2001, paras. 33 to 35. 341 ECHR, Case of A. and Others. v. The United Kingdom, No. 3455/05. Judgment of 19 February 2009, para. 220. The European Court Europeo has indicated that: “[t]he Court further considers that the special advocate could perform an important role in counterbalancing the lack of full disclosure and the lack of a full, open, adversarial hearing by testing the evidence and putting arguments on behalf of the detainee during the closed hearings. However, the special advocate could not perform this function in any useful way unless the detainee was provided with sufficient information about the allegations against him to enable him to give effective instructions to the special advocate. While this question must be decided on a case-by-case basis, the Court observes generally that, where the evidence was to a large extent disclosed and the open material played the predominant role in the determination, it could not be said that the applicant was denied an opportunity effectively to challenge the reasonableness of the Secretary of State’s belief and suspicions about him. In other cases, even where all or most of the underlying evidence remained undisclosed, if the allegations contained in the open material were sufficiently specific, it should have been possible for the applicant to provide his representatives and the special advocate with information with which to refute them, if such information existed, without his having to know the detail or sources of the evidence which formed the basis of the allegations.” “Where, however, the open material consisted purely of general assertions and [the competent organ’s] decision to […] maintain the detention was based solely or to a decisive degree on closed material, the procedural requirements of Article 5 § 4 would not be satisfied.” In this case, the European Court considered that some detainees were not in a position effectively to challenge the allegations against them and, therefore, found that there had been a violation of Article 5.4 of the European Convention. 113