B.2.1) Regarding the immediate opening of an investigation ex officio 124. The Court notes that it is an obligation of the State not only to open an investigation ex officio, but also to do so, as expressly indicated by Article 8 of the Inter-American Convention against Torture, “immediately,” as soon as there is “well-founded reason to believe that an act of torture has been committed.” In this regard, the Court has stated that: Even when the acts of torture or cruel, inhuman or degrading treatment have not been denounced before the competent authorities by the victim himself, in any case in which there is evidence of their perpetration, the State must open, ex officio and immediately, an impartial, independent and thorough investigation that allows the nature and origin of the injuries indicated to be determined, those responsible to be identified, and their prosecution to be undertaken. 140 125. Based on the above, the Court considers that the State’s argument on the failure to denounce the facts and the circumstance that Mr. García Lucero and his family members had recourse to the Inter-American Commission (supra para. 119), does not preclude the State’s obligation to investigate. 141 126. The Court observes that the State became aware of the facts to be investigated on receiving Mr. García Lucero’s letter of December 23, 1993, when he requested the pension as “a person dismissed for political reasons” (supra para. 75). This situation was reaffirmed by the inclusion of Mr. García Lucero’s name on a list in the Valech Commission’s report which also included the names of another 27,153 persons identified as victims (supra para. 72). Also, according to the characterization of events in the 2004 report of the Valech Commission (supra paras. 60 and 72), the acts suffered by Mr. García Lucero between September 16, 1973, and June 12, 1975, could be classified as gross human rights a generalized and systematic attack on sectors of the civilian population,” that “the obligation to investigate and to punish becomes particularly important and powerful.” The Court also indicated that “the prohibition of the forced disappearance of persons and the correlative obligation to investigate this and to punish those responsible has become ius cogens.” The Court indicated that “the facts of the […] case (relating to the practice of forced disappearance, which included in that case, as considered proved, cruel, inhuman and degrading treatment) “violate[d] non-derogable norms of international law (ius cogens),” and, in view of the “nature and severity of the facts,” it considered that “access to justice constitutes a peremptory norm of international law.” In its decision in the case of Gelman v. Uruguay, the Court underscored that “the State obligation to investigate and to punish the human rights violations and to prosecute and punish those responsible, as appropriate, acquired particular importance in view of the seriousness of the crimes committed and the nature of the rights harmed, especially because the prohibition of forced disappearance of persons and its correlative obligation to investigate this and to punish those responsible have, for a long time, been jus cogens.” The express references of the rulings cited relate to acts of forced disappearance of persons. However, it is relevant to recall that the Court has stated that the “prohibition” of “torture and forced disappearance” is a “non-derogable norm of international law or jus cogens” (Case of Goiburú et al. v. Paraguay. Merits reparations and costs. Judgment of September 22, 2006. Series C No. 153, para. 93). Regarding the concept of jus cogens, the International Criminal Tribunal for the former Yugoslavia (ICTY) established that this refers to “a norm that enjoys a higher rank in the international hierarchy than treaty law and even ‘ordinary’ customary rules. The most conspicuous consequence of this higher rank is that the principle at issue cannot be derogated from by States through international treaties or local or special customs or even general customary rules not endowed with the same normative force.” Cf. International Criminal Tribunal for the former Yugoslavia, Prosecutor v. Furundzija, Trial Chamber, Judgment of 10 December 1998, para. 153. 140 Cf. Case of Gutiérrez Soler v. Colombia. Judgment of September 12, 2005. Series C No. 132, para. 54, and Case of Vélez Loor v. Panama. Preliminary objections, merits, reparations and costs. Judgment of November 23, 2010. Series C No. 218, para. 240. Similarly, Case of Cabrera García and Montiel Flores v. Mexico. Preliminary objection, merits reparations and costs. Judgment of November 26, 2010. Series C No. 220, para. 135. 141 The assessment made is in relation to the substantive aspects of the alleged human rights violations. It is not an evaluation of the admissibility of the petition because, as already indicated, the State did not make this argument as a preliminary objection (supra paras. 43 and 44). 40