A/HRC/31/57/Add.3 52. The Special Rapporteur notes the recent efforts made to strengthen procedural safeguards by introducing a number of legal amendments. According to the information provided, the ratio of plea bargaining to total convictions has dropped further; the period of January-June 2015 saw a further drop in the ratio to 64.7 per cent, a decrease of 4.2 per cent compared to the same period in 2014. 53. With regard to the prosecution of cases relating to torture, the Special Rapporteur stresses that obstacles to prosecution, such as amnesty, pardons, statute of limitations or prosecutorial discretion to decline prosecution, are not permissible in international law. Cases of torture must be prosecuted; the only legitimate limitations to this obligation are lack of evidence and the duty to respect guarantees of fair trial and due process of law. The Special Rapporteur notes information according to which prosecutorial discretion to initiate prosecution has never been used in relation to cases of torture. 54. While plea bargaining is not banned in principle, any exercise of prosecutorial discretion in this regard must be subject to scrutiny and to consultation with victims and their families. Importantly, plea bargaining should not be used by defendants who bear or share responsibility for torture to testify against other co-defendants to escape serious punishment. 55. With regard to the national preventive mechanism under the Office of the Public Defender (Ombudsman), the Special Rapporteur learned that, apart from an isolated incident in 2013 when members of the Office were not granted access to a police office, no case of substantial obstruction by the authorities to the Ombudsman when entering prison or police facilities has been reported in the recent past. 56. The Special Rapporteur did, however, receive reports that members of the Special Preventive Group, acting as the national preventive mechanism, were not allowed to bring photographic equipment into prisons during their visits. Given that an important aspect of the methodology laid down by the Optional Protocol to the Convention against Torture is the prerogative of the national preventive mechanism to not merely observe but also document any violation that it may witness, the Special Rapporteur welcomes the adoption on 18 May 2015 of an amendment to the Imprisonment Code removing the abovementioned restrictions. Regrettably, the amendment will not enter into force until 1 September 2016. 1. Office of the Chief Prosecutor 57. The Special Rapporteur welcomes the announcement made by the Chief Prosecutor in March 2015 of the plan to create a department with an investigative mechanism within the Office of the Chief Prosecutor to deal with, inter alia, the large backlog of cases of torture and ill-treatment from the period 1994-2004. Authorities estimated that more than 8,000 victims of abuse from that period await access to remedies, but provided no documentation to support that figure. 58. While the Special Rapporteur understands that the investigative mechanism of the Office of the Chief Prosecutor is not intended to be a substitute for the independent investigation mechanism envisaged in the discussions led by the Inter-Agency Council on Combating Torture and Other Forms of Degrading and Inhuman Treatment or Punishment (see paras. 62-68 below), it is unclear how the new department will interact with the mechanism or whether it will deal only with the backlog or also with ongoing or future cases of torture or ill-treatment. 59. The Special Rapporteur understands that, to date, the department has not announced any investigation of cases of torture or ill-treatment. 10