108. The Court reiterates that Article 13 of the Convention guarantees the availability at the national level of a remedy to enforce the substance of the Convention rights and freedoms in whatever form they might happen to be secured in the domestic legal order. According to the Court's settled case-law, the effect of Article 13 of the Convention is to require the provision of a remedy at national level allowing the competent domestic authority both to deal with the substance of a relevant Convention complaint and to grant appropriate relief, although Contracting States are afforded some discretion as to the manner in which they comply with their obligations under this provision. However, such a remedy is only required in respect of grievances which can be regarded as "arguable" in terms of the Convention (see, among many other authorities, Halford v. the United Kingdom, judgment of 25 June 1997, Reports of Judgments and Decisions 1997-III, p. 1020, § 64).
109. As regards the applicants' complaint of lack of effective remedies in respect of their complaint under Article 2, the Court emphasises that, given the fundamental importance of the right to protection of life, Article 13 requires, in addition to the payment of compensation where appropriate, a thorough and effective investigation capable of leading to the identification and punishment of those responsible for the deprivation of life, including effective access for the complainant to the investigation procedure leading to the identification and punishment of those responsible (see Anguelova v. Bulgaria, No. 38361/97, §§ 161 - 162, ECHR 2002-IV, and v. Turkey, No. 25660/94, § 208, 24 May 2005). The Court further reiterates that the requirements of Article 13 are broader than a Contracting State's obligation under Article 2 to conduct an effective investigation (see Khashiyev and Akayeva, cited above, § 183).
110. In view of the Court's above findings with regard to Article 2, this complaint is clearly "arguable" for the purposes of Article 13 (see Boyle and Rice v. the United Kingdom, judgment of 27 April 1988, Series A No. 131, § 52). The applicants should accordingly have been able to avail themselves of effective and practical remedies capable of leading to the identification and punishment of those responsible and to an award of compensation, for the purposes of Article 13.
111. It follows that in circumstances where, as here, the criminal investigation into the disappearance of two persons has been ineffective and the effectiveness of any other remedy that may have existed, including the civil remedies suggested by the Government, has consequently been undermined, the State has failed in its obligation under Article 13 of the Convention.
112. Consequently, there has been a violation of Article 13 of the Convention in conjunction with Article 2 of the Convention.
113. As regards the violation of Article 3 of the Convention found on account of the applicants' mental suffering as a result of the disappearance of their close relative, their inability to find out what had happened to him and the way the authorities had handled their complaints, the Court notes that it has already found a violation of Article 13 of the Convention in conjunction with Article 2 of the Convention on account of the authorities' conduct that led to the suffering endured by the applicants. The Court considers that, in the circumstances, no separate issue arises in respect of Article 13 in connection with Article 3 of the Convention.
114. As regards the applicants' reference to Article 5 of the Convention, the Court reiterates that, according to its established case-law, the more specific guarantees of Article 5 §§ 4 and 5, being a lex specialis in relation to Article 13, absorb its requirements and in view of its above findings of a violation of Article 5 of the Convention as a result of unacknowledged detention, the Court considers that no separate issue arises in respect of Article 13 read in conjunction with Article 5 of the Convention in the circumstances of the present case.