A/HRC/22/52 bear a share of the State‟s responsibility to secure the realization of the right to truth and the principle of accountability.44 28. Where a plausible allegation is made that public officials have committed (or been complicit in the commission of) gross or systemic human rights violations, the executive authorities of the State(s) concerned are obliged under international law to carry out proprio motu an effective official investigation45 which is begun promptly,46 secures all relevant evidence,47 and is capable of leading to the identification and, where appropriate, the punishment of the perpetrator(s) and those on whose authority the violations were committed.48 Any deficiency in the investigation which undermines its ability to establish the identity of the persons responsible will risk falling foul of the requisite legal standard.49 As the European Court of Human Rights has pointed out, in the absence of such an investigation “it would be possible in some cases for agents of the State to abuse the rights of those within their control with virtual impunity”.50 29. The investigating authorities are obliged to allow victims, or (if deceased) their relatives, effective access to the investigative process,51 respecting their right to be informed and to participate52; to disclose all relevant evidence and findings to the victims, 44 45 46 47 48 49 50 51 52 See Report of the Special Rapporteur on the promotion and protection of human rights and fundamental freedoms while countering terrorism, Compilation of good practices on legal and institutional frameworks and measures that ensure respect for human rights by intelligence agencies while countering terrorism, including their oversight, A/HRC/14/46, (“Best Practice for Intelligence Oversight”) 17 May 2010; see also observations of the High Commissioner for Human Rights in ElMasri, op. cit., footnote 26, at para. 3. ECtHR, El-Masri, op. cit., footnote 26, at paras. 182-185; Assenov v. Bulgaria Application no. 90/1997/874/1086, para 102; Imakayeva v. Russia Application no. 7615/02, paras.164-6; Zontul v. Greece Application no. 12294/07, para 95; IACtHR, Case of the Plan de Sanchez Massacre v. Guatemala, Judgment 9 November 2004 (Reparations and Costs), (Ser. C) No. 116 (2004), (“Plan de Sanchez”), para. 98; United Nations Human Rights Committee, Herrera Rubio v. Colombia, No. 161/1983, 02/11/87, CCPR/C/31/D/161/1983, para 10.5. See also United Nations Principles on the Effective Investigation and Documentation of Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment, adopted by General Assembly Resolution 55/89 of 4 December 2000 (“United Nations Principles on the Investigation of Torture”), and in particular Principles 2, 3a and 4; United Nations Basic Principles on Remedy and Reparation for Gross Human Rights and Humanitarian Law Violations, op. cit., footnote 33, para. 3(b). There is no internationally agreed period of time before which an investigation must begin. However, the Committee Against Torture made clear in Halimi-Nedzibi v. Austria, CAT/C/11/D/8/1991 (para 13.5) that a delay of 15 months was excessive. See also United Nations Joint Study on Secret Detention, op. cit., footnote 1, para. 292(e); Marty III, op. cit., footnote 15, para. 15; and Asia Pacific Forum of National Human Rights Institutions Reference on Torture (2005), p. 129. For a list of mandatory investigative steps see ECtHR, Gül v. Turkey, no. 22676/93, paras. 89-90; also Tanrıkulu v. Turkey, no. 23763/94, para. 109; Salman v. Turkey, no. 21986/93, para. 106; Musayev and Others v. Russia, nos. 57941/00, 58699/00 and 60403/00, para. 162; Nachova and Others v. Bulgaria, nos. 43577/98 and 43579/98, para. 113. See also Marty III, op. cit., footnote 15, para 51. El-Masri, op. cit., footnote 26, para. 182; United Nations Joint Study on Secret Detention, op. cit., footnote 1, para. 292 (e); Marty III, op. cit., footnote 26, para 51 (4.2) (3); ICJ, Questions Relating to the Obligation to Prosecute or Extradite (Belgium v. Senegal) International Court of Justice 20 July 2012, http://www.icj-cij.org/docket/files/144/17064.pdf El-Masri, op. cit., footnote 26, para. 183. El-Masri, op. cit., footnote 26, para. 182. El-Masri, op. cit., footnote 26, para. 185. ECtHR Ognyanova and Choban v. Bulgaria, Application No. 46317/99, para 107; IACtHR, Plan de Sanchez, op. cit., footnote 45, para. 98; United Nations Declaration on Enforced Disappearance, op. cit., footnote 28, Art. 13(4); United Nations Working Group on Enforced and Involuntary Disappearances, General Comment on the Right to the Truth, op. cit., footnote 31, para. 3. 11