A/HRC/13/36 intelligence agencies, including intelligence-gathering, covert surveillance activities, searches and data collection must be regulated by law, monitored by independent agencies, and subject to judicial review. The lack of transparency that prevails in a number of the investigations and trials related to terrorism is a cause for concern. Through the adoption or revival of State secrecy or immunity doctrines or the adoption of other measures to shield intelligence, military or diplomatic sources and information, in the name of national security interests, States have limited the access to the necessary information for an effective investigation and prosecution of cases relating to acts of terrorism. States are required to ensure that confined powers, review of accountability and oversight mechanisms are established against the misuse of exceptional powers granted to intelligence, military agencies or special police to counter terrorism. Such controls might encompass the process or authorizing special powers and the remedies for people claiming abuse of these powers. Controls can occur either before or after the use of powers. 29. The Convention against Torture requires States parties to prevent, within their territory, any acts of torture, or cruel, inhuman or degrading treatment.16 By virtue of the extraterritorial application of the prohibition of such acts, and the obligations under customary international law and Articles 55 and 56 of the Charter of the United Nations, States must also ensure that their officials do not undertake such practices overseas and that they are not complicit in such conduct by other persons. It is thus essential that those responsible for conducting or colluding in interrogation techniques amounting to torture or cruel, inhuman or degrading treatment are held accountable.17 30. The practice of holding terrorist suspects in secret detention has led to the denial of several rights of detainees, not only with respect to their rights associated with liberty, but also for example their right to a fair trial. In such circumstances, where confessions are extracted by torture and evidence gathered illegally through secret agents, the possibility of bringing to justice people who are responsible for committing the above-mentioned violations is unlikely. In its general comment No. 21 on article 10 of the International Covenant on Civil and Political Rights, the Human Rights Committee imposes on States an obligation to individuals who are vulnerable, such as juveniles, due to their status of persons deprived of liberty to be treated with humanity and with respect for the inherent dignity of the human person. 31. Accountability and the right to effective remedies are connected to the right to a fair trial as guaranteed by article 14 of the Covenant, clarified by general comment No. 32 of the Human Rights Committee. Protecting the right of terrorist suspects to a fair trial is critical not only for ensuring that anti-terrorism measures respect the rule of law, but also for ensuring that perpetrators of human rights violations are held accountable. Indeed, violations carried out in the execution of “extraordinary renditions” and collecting evidence by illegal means are very unlikely to be adequately brought to light, and perpetrators brought to justice, if suspects of terrorism are tried in special courts with special procedures or sealed evidence which do not fully guarantee the right to a fair trial. Therefore, the guarantees of a fair trial are essential to ensure accountability and to combat impunity, as well as to provide effective remedies.18 32. Article 10 of the International Covenant on Civil and Political Rights has a clear relationship with the protection from torture, inhuman and degrading treatment and punishment. Human Rights Committee general comment No. 21 clarifies that article 10 16 17 18 12 See CAT/C/USA/CO/2, para. 13, 2006; CAT/C/TGO/CO/1, para. 15, 2006; CAT/C/AUS/CO/3, para. 8, 2008. See A/HRC/10/44/Add.2, para. 64. Human Rights Committee, communication No. 1416/2005, Alzery v. Sweden. GE.10-10442