CCPR/C/115/D/2005/2010 called by the author to adopt.** In that connection, the Committee notes the ruling dated 18 February 2015, by which the United States Court of Military Commission Review, in the case of David M. Hicks v. United States of America, set aside and dismissed the guilty verdict against the author and vacated his sentence, finding that the author’s conviction was unlawfully retrospective. In the Committee’s view, such a judgement casts doubts on whether the determination that the Committee would make with regard to the responsibility borne by Australia would even affect the interests of the United States. The Committee therefore considers that the fact that the United States has not ratified the Optional Protocol does not prevent it from examining the author’s complaints with regard to the responsibility borne by Australia in connection with the period when the author was under the custody of the United States. 2.7 In view of the foregoing, the Committee considers admissible the author’s claims under articles 9 (facts related to the unlawful and arbitrary detention while in United States custody), 7 and 10 (treatment while in United States custody), 14 (unfair trial under United States military commission rules), 15 (retrospective offence), and 2 and 26 (unlawful discrimination on the basis of national origin under the Military Commissions Act), inasmuch as they concern the responsibility of Australia in connection with the period when the author was under the custody of the United States. 2.8 The Committee recalls that, under article 2 (3), States parties have an obligation to ensure that any person whose rights and freedoms recognized in the Covenant are violated shall have an effective remedy. Accordingly, States parties have an obligation to investigate well-founded allegations of torture and other gross violations of human rights promptly and impartially and, if the investigations reveal a violation of article 7, to ensure that those responsible are brought to justice 2.9 The author claims that Australia has not taken steps to investigate his allegations of torture in the custody of the United States, in violation of articles 2 and 7 of the Covenant. The State party argues that this claim should be held inadmissible ratione materiae as there is no duty set forth in the Covenant to investigate allegations of torture relating to conduct outside the jurisdiction of a State party. However, the Committee takes note of the fact which is not disputed by the State party - that Australian officials interviewed the author several times while he was in the custody of the United States. It also notes that, according to Australia, Australian agents took a certain number of measures to investigate allegations of torture or inhuman treatment against their nationals held in the custody of the United States, including the author. The Committee considers that the argument formulated by the State party raises issues that are closely linked to the merits of the case and should be reviewed at that stage. As no other issues regarding the admissibility of the present claim arise, the Committee considers it admissible. 2.10 The author claims to be a victim of violations by the State party of his rights under the Covenant in connection with his imprisonment in Australia, from 20 May to 29 December 2007, and the ensuing one-year control order imposed on him by the Federal Magistrates Court of Australia, which expired on 21 December 2008. His imprisonment in Australia was the result of a sentence to seven years’ imprisonment (with six years and three months thereof suspended) imposed by a United States Military Commission on 31 March 2007 and a bilateral prisoner transfer arrangement between the United States and ** See Case concerning certain phosphate lands in Nauru (Nauru v. Australia) (Preliminary Objections), Reports of Judgments, Advisory Opinions and Orders, judgment of 26 June 1992, I.C.J. Reports 1992, p. 240, para. 55; Case of armed activities on the territory of the Congo (Democratic Republic of the Congo v. Uganda), judgment of 19 December 2005, I.C.J. Reports 2005, p. 168, paras. 203-204. 5