A/HRC/13/39/Add.5 145. In order to make sure that the perpetrators of torture are prosecuted and punished, making torture an offence under criminal law with an adequate sanction is not sufficient. States have to guarantee that the criminal prohibition of torture is adequately applied. To this regard States have to guarantee the separation of powers, particularly the independence of the judiciary. When the cooperation between the police, prosecution services and judges is too close, judges might refrain from sentencing police offers or applying the law with the required stringency. (b) Independent body for the investigation of torture 146. As outlined above, one of the main factors conducive to torture and leading to impunity for the perpetrators, is the lack of a prompt and independent investigation into allegations of torture or ill-treatment. Articles 12 and 13 CAT contain two of the most important provisions for the prevention of torture and ill-treatment: the obligation of States parties to investigate every potential case of torture and ill-treatment, either on the basis of an allegation by the victim (article 13) or ex officio on the basis of any reasonable ground to believe that an act of torture or ill-treatment has been committed (article 12). 147. There are plenty of opportunities for public prosecutors, police chiefs and prison directors to commence investigations if they are genuinely interested in preventing torture and cruel, inhuman or degrading treatment: Lawyers, doctors and family members might be encouraged to report allegations; independent prison inspection commissions, national human rights institutions or NGOs might be asked to find out whether torture practices exist in any given detention facility; boxes for depositing allegations might be established in all places of detention. Such investigations might at times lead to a full criminal investigation or even prosecution. Sometimes a disciplinary sanction or a better knowledge about the risks of torture and how such risks can more effectively be prevented might be sufficient. In other cases, the facts are established by civil courts in the context of civil proceedings leading to reparation for victims of torture. 148. While investigations by police chiefs, prison directors and public prosecutors often are necessary as a first step for a prompt investigation, it is advisable not to entrust the investigation solely to persons who have close personal or professional links with the persons suspected of having committed torture or ill-treatment, or who may have an interest in protecting these persons or the particular unit to which they belong. It is not surprising that countries where only police officers are investigating allegations against the police, military officers against the military and so on, are often not able to present a single conviction for torture, despite well-founded allegations to the contrary.87 149. When impartial and vested with full investigative powers, competent authorities for investigations into torture allegations include inter alia courts, national human rights institutions, ombuds-institutions, detention monitoring commissions, public prosecutors and special independent police investigators entrusted with the sole task of investigating torture and CIDT by police officials (so-called ‘police-police’). While NHRI’s, ombudsinstitutions and detention monitoring commissions usually lack full powers of criminal investigations, a special ‘police-police’, if truly independent from the police, may be in a better position to collect the evidence necessary to bring the perpetrators of torture to justice. 150. I was time and again confronted with the argument by State officials that torture allegations do not have to be taken seriously because criminals are not trustworthy and have a particular interest to fabricate such allegations in order not to be convicted. It shall not be 87 38 A/HRC/4/33/Add.3, para 54.