KURT JUDGMENT OF 25 MAY 1998 36 investigation were further compounded by the fact that the task of taking witness statements from villagers was entrusted to the gendarmes against whom the complaint had been made (see paragraph 38 above). For these reasons the Commission found that the authorities were in breach of Article 13. 139. The Court recalls that Article 13 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. The effect of Article 13 is thus to require the provision of a domestic remedy to deal with the substance of the relevant Convention complaint and to grant appropriate relief, although Contracting States are afforded some discretion as to the manner in which they conform to their Convention obligations under this provision. The scope of the obligation under Article 13 varies depending on the nature of the applicant’s complaint under the Convention. Nevertheless, the remedy required by Article 13 must be “effective” in practice as well as in law, in particular in the sense that its exercise must not be unjustifiably hindered by the acts or the omissions of the authorities of the respondent State (see the above-mentioned Aksoy judgment, p. 2286, § 95; the abovementioned Aydın judgment, pp. 1895-96, § 103; and the above-mentioned Kaya judgment, pp. 325–26, § 89). 140. In the instant case the applicant is complaining that she has been denied an “effective” remedy which would have shed light on the whereabouts of her son. She asserted in her petitions to the public prosecutor that he had been taken into custody and that she was concerned for his life since he had not been seen since 25 November 1993. In the view of the Court, where the relatives of a person have an arguable claim that the latter has disappeared at the hands of the authorities, the notion of an effective remedy for the purposes of Article 13 entails, 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 and including effective access for the relatives to the investigatory procedure (see, mutatis mutandis, the above-mentioned Aksoy, Aydın and Kaya judgments at p. 2287, § 98, pp. 1895–96, § 103 and pp. 329–31, §§ 106 and 107, respectively). Seen in these terms, the requirements of Article 13 are broader than a Contracting State’s obligation under Article 5 to conduct an effective investigation into the disappearance of a person who has been shown to be under their control and for whose welfare they are accordingly responsible. 141. For the reasons given earlier (see paragraphs 124 and 126 above), Mrs Kurt can be considered to have had an arguable complaint that her son had been taken into custody. That complaint was never the subject of any serious investigation, being discounted in favour of an unsubstantiated and hastily reached explanation that he had been kidnapped by the PKK. The