KURT JUDGMENT OF 25 MAY 1998 32 exceptions to a most basic guarantee of individual freedom (see, mutatis mutandis, the Quinn v. France judgment of 22 March 1995, Series A no. 311, p. 17, § 42). 123. It must also be stressed that the authors of the Convention reinforced the individual’s protection against arbitrary deprivation of his or her liberty by guaranteeing a corpus of substantive rights which are intended to minimise the risks of arbitrariness by allowing the act of deprivation of liberty to be amenable to independent judicial scrutiny and by securing the accountability of the authorities for that act. The requirements of Article 5 §§ 3 and 4 with their emphasis on promptitude and judicial control assume particular importance in this context. Prompt judicial intervention may lead to the detection and prevention of life-threatening measures or serious illtreatment which violate the fundamental guarantees contained in Articles 2 and 3 of the Convention (see, mutatis mutandis, the above-mentioned Aksoy judgment, p. 2282, § 76). What is at stake is both the protection of the physical liberty of individuals as well as their personal security in a context which, in the absence of safeguards, could result in a subversion of the rule of law and place detainees beyond the reach of the most rudimentary forms of legal protection. 124. The Court emphasises in this respect that the unacknowledged detention of an individual is a complete negation of these guarantees and a most grave violation of Article 5. Having assumed control over that individual it is incumbent on the authorities to account for his or her whereabouts. For this reason, Article 5 must be seen as requiring the authorities to take effective measures to safeguard against the risk of disappearance and to conduct a prompt effective investigation into an arguable claim that a person has been taken into custody and has not been seen since. 125. Against that background, the Court recalls that it has accepted the Commission’s finding that Üzeyir Kurt was held by soldiers and village guards on the morning of 25 November 1993. His detention at that time was not logged and there exists no official trace of his subsequent whereabouts or fate. That fact in itself must be considered a most serious failing since it enables those responsible for the act of deprivation of liberty to conceal their involvement in a crime, to cover their tracks and to escape accountability for the fate of the detainee. In the view of the Court, the absence of holding data recording such matters as the date, time and location of detention, the name of the detainee as well as the reasons for the detention and the name of the person effecting it must be seen as incompatible with the very purpose of Article 5 of the Convention. 126. Furthermore, the Court considers that having regard to the applicant’s insistence that her son was detained in the village the public prosecutor should have been alert to the need to investigate more thoroughly her claim. He had the powers under the Code of Criminal Procedure to do