24 A practical guide to the Istanbul Protocol – for lawyers have concluded that investigations must be carried out promptly.70 The Special Rapporteur on Torture71 as well as instruments such as the Body of Principles for the Protection of All Persons under Any Form of Detention or Imprisonment72 and the Standard Minimum Rules for the Treatment of Prisoners73 have emphasised that complaints about torture should be investigated promptly. The Human Rights Committee declared in its General Comment 20, “complaints must be investigated promptly and impartially by competent authorities so as to make the remedy effective.” It has repeatedly emphasised that a “State party is under an obligation to investigate, as expeditiously and thoroughly as possible, incidents of alleged ill-treatment of inmates.”74 In its consideration of State party reports, the Human Rights Committee has also repeatedly called upon States to “ensure that all instances of ill-treatment and of torture and other abuses committed by agents of the State are promptly considered and investigated by an independent body.”75 When examining whether an investigation is effective, the European Court of Human Rights has applied the test of whether “the authorities reacted effectively to the com76 plaints at the relevant time.” The Court has in several cases based its finding of a failure by the authorities to investigate on the lack of prompt and timely investigations. Considerations are given to the starting of investigations,77 delays in taking 78 statements, and the length of time taken during the initial investigations.79 Equally, the Inter-American Court of Human Rights has not specified the meaning of “promptness.” However in Cantoral Benavides v Peru, when considering the failure of the State party to open a formal investigation following an allegation of torture, the Court referred to Article 8 of the InterAmerican Convention against Torture which “clearly sets forth the obligation of the State to proceed as a matter of routine and immediately in cases such as the present case,” thus implying a literal meaning.80 2. OBLIGATION OF STATES TO INVESTIGATE THE ALLEGATION “IMPARTIALLY” AND THE QUESTION OF INDEPENDENCE OF INVESTIGATING BODIES The Istanbul Protocol provides that independent investigative mechanisms should be established. It gives examples of different grounds for requiring an independent investigative mechanism, such as insufficient expertise or lack of impartiality of investigators; the existence of a pattern of abuse (e.g. where the type of torture practised is attributable to public officials); the suspected involvement of public officials (e.g. where the national authorities have attempted to obstruct or delay the investigation of torture); or where the public interest would be served by creating an independent mechanism. Impartiality has been described as a key, if not the most important, requirement of the investigation process.81 The term “impartiality” means free from undue bias. It is conceptually different from “independence” which denotes that the investigation is not in the hands of bodies or persons who have close personal or professional links with the alleged perpetrators.82 The two notions are, however, closely interlinked, as the lack of independence is commonly seen as an indicator of partiality.83 Articles 12 and 13 of the Convention against Torture and Article 8 of the Inter-American Convention to Prevent and Punish Torture expressly require investigations to be impartial. The Human Rights Committee has also found impartiality to be an implicit requirement for any investigation contemplated by Article 7 of the International Covenant on