such grounds and in accordance with such procedure as are established by law. Convention on the Rights of the Child Article 37 b No child shall be deprived of his or her liberty unlawfully or arbitrarily. The arrest, detention or imprisonment of a child shall be in conformity with the law and shall be used only as a measure of last resort and for the shortest appropriate period of time. The Beijing Rules Rule 13.1. Detention pending trial shall be used only as a measure of last resort and for the shortest possible period of time. Rule 10.2 A judge or other competent official or body shall, without delay, consider the issue of release. Recommendation of the European Committee for the Prevention or Torture and Inhuman or Degrading Treatment or Punishment (CPT), stipulated in the report on the visit in Poland in 2004, for the Polish government (Council of Europe, Strasburg, 11.04.2005); CPT (2005)3. § 10 Having in mind that police establishments for children are not adapted for prolonged stays, the CPT recommends that the Polish authorities make strenuous efforts to ensure that the legal provisions on the duration of custody in a police establishment for children are respected in practice.. According to Article 40 of the Act on juvenile delinquency proceedings of 26 October 198252(hereinafter: j.d.p.) the Police is authorised to detain a juvenile in emergency centre for children on reasonable suspicion of having committed an offence, if there exists a justified concern that they may hide themselves or erase the traces of the offence or it is impossible to establish identity of the juvenile (then, the stay cannot exceed 72 hours.) Moreover, a juvenile can be held in ECC during an arbitrary stay outside a juvenile shelter or juvenile detention centre (up to 5 days.) The National Preventive Mechanism paid particular attention to the period of time for which a juvenile lived in emergency children centres and the grounds on which they were held there (gathered information concerned year 2009 and 2010.) The problem of long lasting stays in this type of facilities was very important in the Police Emergency Centre for Children in Legnica, with 13% of children staying for longer than 5 days. In the Police Emergency Centre for Children in Tarnów, the longest stay of a detained person was 29 days. In response to all the remarks of the Mechanism, the Voivodeship Police Commander in Wrocław explained that the main reason of the extended stays of detained persons is limited number of free places in juvenile shelters. It results from the lack of legal regulation determining the period o stay of a juvenile in the centre after the decision on a juvenile placement in a juvenile shelter and for that reason the juveniles have to wait for several days for being transported to another facility. The National Preventive Mechanism is of the opinion that such a decision should be implemented immediately. They focused also on a juvenile placement in a Centre based on a warrant of the court concerning a juvenile compulsory appearance in a foster care centre (youth care centre and youth sociotherapy centre.) According to the Prevention Department of the Voivodeship Police Commander Office in Wrocław a relevant court warrant or decision authorizes it pursuant to Article 67 of the Act on j.d.p. (“ When it comes to                                                              52 Dz.U. of 2002 No 11, item. 109 as amended.