A/HRC/4/40/Add.4 page 12 within three days of the preliminary hearing. Pretrial detention, that is preventive detention between the first appearance before a judge and the final decision on the case, can be ordered under one of the following circumstances: − Risk of flight of the accused; − Possible obstruction to the investigation by the accused; − Well-founded risk that the accused may rejoin the criminal organization to which he is suspected of belonging; − Well-founded risk that the accused may make attempts on the life or other reprisals against those who accused or denounced him (CPP, art. 178). 38. Orders of preventive detention are subject to appeal before an appellate court which shall rule within three days. 39. Preventive detention can last for a maximum of two years on charges for offences carrying out six or more years of imprisonment, and up to one year for lesser offences. In cases in which the evidence to be gathered is particularly extensive or complex, the Supreme Court can exceptionally extend these maximum terms by six months. In no case may the duration of preventive detention exceed more than half the minimum sentence available for the offence (CPP, art. 181). Once the accused has been convicted in first instance, preventive detention can be extended for up to half the duration of the pronounced sentence (CPP, art. 181.4). 40. Once the preventive detention of an accused has reached its maximum duration the judge must provisionally release the detainee and decide on an alternative preventive measure (CPP, art. 181.5). However, according to an amendment introduced in January 2005 regarding detainees charged with being members of an illicit association, preventive detention can never be substituted with an alternative measure (CPP, art. 184.6). 41. Preventive detention is forbidden in cases where the offence carries a maximum sentence of less than five years’ imprisonment (CPP, art. 182), except if there is a reasonable suspicion that the accused may make reprisals against those who accused or denounced him. 42. If the accused is acquitted, the court shall order the immediate release. However, until the acquittal has become final, the court may, upon request of the prosecutor, continue to impose preventive measures in order to ensure that the accused remain at the disposal of the court, insofar as such measures do not involve deprivation of liberty (CPP 339.2-3). (d) Alternative measures to preventive detention 43. As already mentioned, the Criminal Procedure Code provides for a number of alternative security measures, such as house arrest, obligation to report to the judge or other surveillance authority, prohibitions to visit certain places or meet certain persons, and financial guarantees.