A/HRC/45/13/Add.3 investigations, in order to restrict the participation of institutions and agencies that are suspected of committing or having committed enforced disappearances. 41. Investigation, criminal prosecutions and trials by the agencies involved in the alleged enforced disappearance have also often led to the violation of the rights of those accused of committing this crime, who are denied due process, including fair treatment at all stages of the proceedings and judicial guarantees before a competent, independent, transparent and impartial court of law.37 42. Nevertheless, any limitation of military jurisdiction should not serve as an excuse for the armed forces or other law enforcement or intelligence bodies to withhold full cooperation with the civilian authorities in charge of the investigation. On the contrary, the former should ensure unfettered and immediate access to potential detention sites and relevant documentation and guarantee that their personnel can be heard as witnesses without any pressure or limitations. They must also ensure that arrest warrants against their members are duly executed. G. Inadmissibility of defence of superior orders 43. In the context of transitions to democracy, attempts have often been made to use criminal law in order to obtain exemption from responsibility for those who carried out enforced disappearances by invoking compliance with orders from their superiors. For this reason, article 6 of the Declaration established that no order or instruction from a public authority, whether civil, military or any other, may be invoked to justify an enforced disappearance. Any person who receives such an order or instruction has the right and duty not to obey it.38 The same norm established the obligation of States to prohibit this type of legislation in relation to enforced disappearances and the requirement to train law enforcement officials accordingly. 44. The Working Group has emphasized that none of the human rights instruments on enforced disappearance recognize due obedience as grounds to mitigate criminal sanctions and that, should any legislation contemplate it, the legislation should never go against the obligation to apply sanctions in accordance with the extreme seriousness of the offence.39 The Working Group has also stated that an order to commit or participate in any way in an act of enforced disappearance is manifestly unlawful and should be interpreted as such by the courts.40 H. Statute of limitations and the principle of ne bis in idem 45. Article 17 of the Declaration establishes that, when the remedies provided for in article 2 of the International Covenant on Civil and Political Rights are no longer effective, the statute of limitations relating to acts of enforced disappearance shall be suspended until these remedies are effectively re-established.41 46. It also provides that, where statutes of limitations exist relating to acts of enforced disappearance, they should be proportionate to the extreme seriousness of the crime. If applicable, the statute of limitation must only begin once the act of enforced disappearance has ceased.42 This is reiterated in article 8 of the International Convention on the Protection of All Persons from Enforced Disappearance. 37 38 39 40 41 42 Inter-American Court of Human Rights, Rodríguez Vera et al. v. Colombia, Judgment, 14 November 2014, para. 490. See also International Convention, art. 6 (2). A/HRC/16/48/Add.3, para. 52; Declaration, art. 4 (1); E/CN.4/2005/102/Add.1, principle 27 (a); and A/HRC/33/51/Add.1, paras. 19–20. A/HRC/16/48/Add.3, para. 53. E/CN.4/2001/68, paras. 27–28. See, for example, A/HRC/27/49/Add.1, paras. 39 and 41; and A/HRC/33/51/Add.1, para. 19. See also references to Chile, Ecuador and France in para. 94 of the annex. 9