A/HRC/4/40/Add.4 page 8 convicts are respected. In discharging his or her duties, the juez de ejecución hears and rules on requests from detainees regarding conditional release, complaints of unlawful disciplinary measures and violations of their fundamental rights (CPP, arts. 60 and 381-382). In addition, the juez de ejecución keeps track of the time spent in custody, including in pretrial detention (which is to be subtracted from the sentence). Therefore, the juez de ejecución also rules on the timeliness of applications for conditional release, and keeps both the detainee and the prison authorities informed on these matters. Prison authorities are required to duly register such information (CPP, art 386). For their parts, the public prosecutor and the convict can bring to the attention of the juez de ejecución all questions pertaining to the execution of a sentence and conditional release. The juez de ejecución issues rulings on such matters after having held oral hearings (CPP, art. 386). 14. The juez de ejecución is also responsible for monitoring the strict enforcement of the principle according to which preventive detention may not assume the nature of a sanction and should only be used to prevent flight, obstruction of justice or further criminal activity. In case of non-compliance with such rules, the juez de ejecución promptly informs the judge in charge of the criminal proceedings, who should, within 24 hours, rule on the matter. 3. The Public Prosecution Service 15. The Law of 1994 regulating public prosecution establishes a Public Prosecution Service independent of the other branches of Government. It is responsible, inter alia, for investigating and prosecuting the case and for ensuring that the constitutional rights of the accused are respected. According to article 33 of the Law, public prosecutors participate directly in the investigation: they direct and supervise the police during the course of the investigation; decide whether to bring charges against suspects and act as prosecutors during the trial. 16. The 1994 Law on public prosecution provided the establishment of a directorate of criminal investigation (DGIC), under the responsibility of the Public Prosecution Service (art. 41). However, the 1998 Law on the National Police, reallocated investigation to the Ministry of Security, leaving the Public Prosecution Service in charge only of providing guidance to the Dirección General de Investigación Criminal (DGIC), which, under the new law, acts under the authority of the police. The CPP of 2002 defines the relationship between the Public Prosecution Service and the police and its article 279 prescribes that in discharging their duties the members of DGIC act on their own initiative, in accordance with the general guidelines (orientaciones) provided by prosecutors and execute orders received from the prosecutors. 17. In recent years, specialized prosecution sections have been established within the Public Prosecution Service, inter alia to follow cases relating to violations of human rights, offences against women, protection of children, etc. 4. The National Police 18. Until the 1990s, when it was placed under civilian control, the National Police were under the authority of the Ministry of Defence. They are now governed by the Law on the National Police of 1998 and come under the authority of the Ministry of Security.