E/CN.4/2006/6 page 13 the force applied in a particular situation.2 Disproportionate or excessive exercise of police powers amounts to CIDT and is always prohibited. But the principle of proportionality, which assesses the lawful use of force to fall outside the scope of CIDT, only applies in situations in which the person concerned is still in a position to use force in turn against a law enforcement official or a third person. As soon as that person ceases to be in a position to resist the use of police force, i.e. is under the control of a law enforcement official and becomes powerless, the principle of proportionality ceases to apply. Powerlessness of the victim 39. It is the powerlessness of the victim in a given situation that makes him or her particularly vulnerable to any type of physical or mental pressure. Torture, as the most serious violation of the human right to personal integrity and dignity, presupposes a situation where the victim is powerless i.e. is under the total control of another person. This is usually the case with deprivation of personal liberty.3 Indeed, a thorough analysis of the travaux préparatoires of articles 1 and 16 of CAT as well as a systematic interpretation of both provisions in light of the practice of the Committee against Torture leads one to conclude that the decisive criteria for distinguishing torture from CIDT may best be understood to be the purpose of the conduct and the powerlessness of the victim, rather than the intensity of the pain or suffering inflicted, as argued by the European Court of Human Rights and many scholars. 40. Similarly, notwithstanding the principle of proportionality of the use of force as a determinant of CIDT, the overriding factor at the core of the prohibition of CIDT is the concept of powerlessness of the victim. In other words, as long as a person is able to resist the use by law enforcement officials of the degree of force legitimately required by the exigencies of the situation, the use of force falls outside the scope of the prohibition of CIDT. But from the moment the person concerned is under the de facto control of the police officer (e.g. hors de combat, otherwise unable to resist or flee a premises, is arrested and handcuffed, detained in a police van or cell, etc.), the proportionality test ceases to be applicable and the use of physical or mental coercion is no longer permitted. If such coercion results in severe pain or suffering inflicted to achieve a certain purpose, it must even be considered as torture. If interrogation methods do not reach the level of severe pain or suffering but are intended to humiliate the detainee, they are still to be considered as degrading treatment or punishment in violation of article 16 of CAT and/or article 7 of ICCPR. In addition, article 10 of ICCPR establishes a particular right to be treated in a humane and dignified manner which only applies to persons deprived of their personal liberty. Conclusion 41. The distinction between torture and CIDT is an important one and relates primarily to the question of personal liberty. Outside a situation where one person is under the de facto control of another, the prohibition of CIDT is subject to the proportionality principle, which is a precondition for assessing its scope of application. However, if a person is detained or otherwise under the de facto control of another person, i.e. powerless, the proportionality test is no longer