26. In the case in point, the State alleges that the petitioners should have availed themselves of remedies linked to the jurisdiction that reviews final administrative court decisions, such as acción de tutela, before taking their case to the Commission. However in cases involving allegations of presumed human rights violations, such as those reported in this case, the IACHR has established that the decisions of administrative review courts are exclusively mechanisms for supervision of the administrative operations of the State designed to obtain compensation for damages caused by abuse of authority.5 In general, this type of procedure, like the recurso de tutela, does not constitute an adequate mechanism in and of itself to compensate for human rights violations such as the ones reported, or to satisfy the duty of judicial clarification of crimes. Therefore, it is not necessary for this type of remedy to be exhausted in a case such as the present one. In addition, it is appropriate to clarify whether the acción de tutela referred to by the State has to do with a proceeding against Soldier Tabares Toro that is not related to the acts reported by the petitioners pertaining to the forced disappearance of the soldier in question. 27. As for application of the exception to compliance with the requirement of exhaustion of domestic remedies invoked by the petitioners, Article 46(2) of the Convention establishes that this requirement is not applicable when: a. the domestic legislation of the state concerned does not afford due process of law for the protection of the right or rights that have allegedly been violated; b.the party alleging violation of his rights has been denied access to the remedies under domestic law or has been prevented from exhausting them; or c. there has been unwarranted delay in rendering a final judgment under the aforementioned remedies. In their petition, the petitioners invoke application of the exception related to unwarranted delay in the administration of justice, based on the duration of the preliminary investigation stage in the proceedings opened in the present case, which has extended over a period of more than four years. The State, for its part, alleges that the prolonged time of the preliminary stage is reasonable, in view of the complexity of the investigation and the impossibility of gaining access to the area where the events occurred in order to complete the taking of evidence. 28. The Commission notes that, in accordance with the information provided by the parties, over six years have elapsed since the beginning of the preliminary investigation, and that the investigation has not even yet resulted in the first stage of a criminal trial. On the basis of the elements of proof produced in the past six years, the whereabouts of Iván Tabares Toro has not been determined and the persons presumably responsible for his forced disappearance have not been identified. 29. In this regard the IACHR has repeatedly maintained that criminal investigations must be conducted promptly, in order to protect the interests of the victims, preserve the evidence, and even to safeguard the rights of any persons considered as suspects in the context of the investigation. According to the InterAmerican Court, although any criminal investigation must comply with a series of legal requirements, the rule of prior exhaustion of domestic remedies should not lead 5 IACHR, Report N° 15/95, 1995 Annual Report of the IACHR, paragraph 71; Report N° 61/99, 1999 Annual Report of the IACHR, paragraph 51.