11 49. In this regard, Nicaragua declared that it had repeatedly raised the objection that domestic remedies had not been exhausted before the Commission, “since the very beginning” of the proceeding before the Commission, specifically, in its reply to the memorandum of understanding presented by the petitioners within the framework of the friendly settlement and, in repeated briefs while the case was being processed, including those of November 5, December 4 and 19, 1997, February 14 and March 2, 1998. Further still, this position was manifested by Government representatives in hearings held at the seat of the Commission on March 4, 1997, and subsequently, in October the same year. Thus, Nicaragua stated that these communications demonstrated that, at no time, had it renounced, either tacitly or expressly, its right to assert this objection. 50. On this aspect, the Commission indicated that, according to the principle of estoppel, the State was impeded from alleging the objection of failure to exhaust domestic resources, because after a long process of meetings with the Commission and the Community “it [was] the first time in the history of the case that the State [had] presented the argument that domestic remedies had not been exhausted due to a procedural error by the victims”. Furthermore, it indicated that “[s]ubsequent communications from the State arguing failure to exhaust domestic remedies did not reach the Commission until November 1997, and did not refer to the Community’s first application for amparo, but rather to the second application and to applications for amparo filed by other parties opposed to granting the concession to SOLCARSA.” It added that the State could not file an objection that domestic remedies had not been exhausted after it had taken part in the friendly settlement procedure during two years. 51. In addition, the Inter-American Commission stated that, even if the State might have avoided the tacit waiver due to silence, its reply to the Commission’s Report No. 27/98 of May 7, 1998, did not pose any objection, but rather was dedicated to responding to the Commission’s recommendations, thereby acknowledging its responsibility. In this way, the Commission concluded that the State’s conduct constituted a waiver of any objection that domestic remedies had not been exhausted, which it might have alleged previously. * * * 52. Article 46.1a of the Convention establishes that, in order for a petition or communication presented to the Inter-American Commission pursuant to Articles 44 or 45 of the Convention to be admissible, it is necessary that the remedies under domestic law have been pursued and exhausted. The Court considers it necessary to emphasize that, with regard to the matter referred to in the objection filed by the State, it has established criteria that should be taken into consideration in this case. 53. Indeed, of the generally recognized principles of international law referred to in the rule on exhaustion of domestic remedies, the foremost is that the State defendant may expressly or tacitly waive invocation of this rule (Castillo Páez Case, Preliminary Objections. Judgment of January 30, 1996. Series C No. 24, para. 40; Loayza Tamayo Case, Preliminary Objections. Judgment of January 31, 1996. Series C No. 25, para. 40). Secondly, in order to be timely, the objection that domestic remedies have not been exhausted should be raised during the first stages of the proceeding or, to the contrary, it will be presumed that the interested State has