Chapter 8 • International Legal Standards for the Protection of Persons Deprived of Their Liberty treatment of any individual subjected to any form of arrest, detention or imprisonment must receive appropriate instruction and training.”66 As indicated above, and as explained in Chapters 4 and 7, confessions may not be obtained by illegal means such as torture or other forms of ill-treatment or human rights violations. Guideline 16 of the Guidelines on the Role of Prosecutors provides that prosecutors “shall refuse to use such evidence against anyone other than those who used such methods, or inform the Court accordingly, and shall take all necessary steps to ensure that those responsible for using such methods are brought to justice” (for a similar rule, see also art. 15 of the Convention against Torture). States have a legal duty under international law to take effective legislative, administrative, judicial and other measures to prevent acts of torture and other forms of ill-treatment. States also have a legal duty to investigate promptly and effectively alleged instances of torture and other forms of ill-treatment and to provide effective remedies to alleged victims of such treatment. To grant immunity to perpetrators of torture or other forms of ill-treatment is incompatible with States’ legal duty to prevent, investigate and remedy human rights violations. Every person has the right not to be subjected to torture or to cruel, inhuman or degrading treatment or punishment, and this right must be guaranteed at all times, and cannot be derogated from even in public emergencies threatening the life of the nation. In general, it can be said that torture is a particularly severe form of ill-treatment aimed either at obtaining confessions or information from a person or punishing or intimidating him or her. It is committed by a public official, or at the instigation of or with the consent or acquiescence of such official or other person acting in an official capacity. Sexual abuse in the form of rape, committed by public officials, has been considered to constitute a form of torture. The right to freedom from ill-treatment comprises the prohibition on corporal punishment and, as a minimum, medical and scientific experimentation that has not been freely consented to. All persons deprived of their liberty must also be treated with respect for the inherent dignity of the human person. Law enforcement officials and medical personnel are strictly forbidden to resort to torture and other forms of ill-treatment at any time. Confessions obtained by such treatment must be disregarded by prosecutors and judges. 66 United Nations Compilation of General Comments, p. 140, para. 10; emphasis added. Human Rights in the Administration of Justice: A Manual on Human Rights for Judges, Prosecutors and Lawyers 333