A/HRC/4/40 page 21 45. In international human rights law the principle of non-refoulement is explicitly contained in article 3 of the Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment, which prohibits the removal of a person to a country where there are substantial grounds for believing that he or she would be in danger of being subjected to torture. Under the International Covenant on Civil and Political Rights, though not explicitly enshrined in a separate provision, the obligation not to extradite, deport, expel or otherwise remove a person is not limited to the risk of torture but extends also to violations of the right to life and to cruel, inhuman or degrading treatment or punishment.11 46. While many bilateral and multilateral treaties provide for the possibility of denying a request for extradition if there are well-founded concerns that the person to be extradited would not enjoy a fair trial in the receiving State, the reluctance of States and international human rights bodies to extend the application of the prohibition of refoulement to the rights protected by articles 9 and 14 of the Covenant is comprehensible. It would constitute a considerable obstacle to the legitimate faculty to deport or expel non-citizens if the sending State had to assess in every case whether the person concerned would be at risk of not being tried within a reasonable time if charged, or of not being compensated if unlawfully arrested, or of not having “adequate time and facilities for the preparation of his defence” if charged and tried - particularly as deportation and expulsion are generally not connected to criminal charges in the receiving State. 47. The principle of non-refoulement remains, however, relevant also with regard to arbitrary detention. Where there are substantial grounds for believing that there is a real risk that the person to be removed from the territory will be deprived of his or her liberty in the receiving State (as is often the case when the ground for removal is a suspicion of involvement in terrorist activities), the sending State should examine whether such detention would be arbitrary within the meaning of the three categories of arbitrary detention identified in the Working Group’s methods of work: − Deprivation of liberty without legal basis; − Deprivation of liberty to repress the exercise of fundamental freedoms, such as freedom of religion, freedom of opinion, freedom of association; − Deprivation of liberty in grave violation of international fair-trial norms. 48. In many cases this test will overlap with the prohibition of refoulement already mandatory for States under international treaty and customary law: prolonged incommunicado detention and indefinite detention can both amount to inhuman treatment;12 deprivation of liberty 11 See, for example, Human Rights Committee general comment No. 31 on article 2 of the Covenant, paragraph 12. 12 As stated by the Commission on Human Rights in its resolution 2003/38, “prolonged incommunicado detention may facilitate the perpetration of torture and can in itself constitute a form of cruel, inhuman or degrading treatment”.