A/HRC/4/40 page 23 United Nations Model Treaty on Extradition, that extradition shall be refused if there is a risk of a trial falling short of article 14 guarantees in the receiving country, then extradition must be refused if there is such a risk, and no diplomatic assurances (which would constitute recognition of the existence of the risk) can legitimately overcome the obstacle. Similarly, if extradition is possible in the absence of a treaty on the basis of the domestic legislation of the sending country, diplomatic assurances cannot be used to circumvent a prohibition on extradition if there is a risk of arbitrary detention or unfair trial. 54. A second precondition is that the sending State has reason to consider the assurances reliable and that the authority in the receiving State that is giving the assurances is in fact in a position to ensure compliance. 55. Thirdly, diplomatic assurances can never be acceptable where the sending Government has substantial grounds for believing that there is a real risk of treatment contrary to article 7 of the Covenant upon removal. In this respect, the Working Group agrees with the Special Rapporteur on torture, inhuman or degrading treatment or punishment in rejecting diplomatic assurances as “unreliable and ineffective” insofar as torture is concerned.13 56. In the end, diplomatic assurances regarding detention and trial can be a legitimate means only when, on the one hand, the prohibition of refoulement does not otherwise impede the removal (in particular, no risk of torture or other ill-treatment) and, on the other hand, the guarantees provided by extradition proceedings are not available. Instead of such diplomatic assurances, however, the Working Group notes a phenomenon that could be named “reverse diplomatic assurances”. G. “Reverse diplomatic assurances” 57. Whereas in the case of diplomatic assurances a sending Government seeks from the receiving Government a (however ineffective) guarantee that the person extradited, deported or expelled will not be subjected to treatment contrary to human rights norms, in the case of “reverse diplomatic assurances” the sending Government seeks precisely assurances that the person handed over will be deprived of liberty, although there are no criminal charges against him and no other legal basis for detention. The cases in Opinion No. 47/2006 are an example of this practice. The Working Group has also received information that in its efforts to move detainees from so-called “black sites” and from the Guantánamo Bay detention facilities to the detainees’ country of origin or third countries, the United States Government is seeking such “reverse diplomatic assurances”, i.e. asking receiving Governments to detain the persons handed over despite the absence of criminal charges or to otherwise indefinitely place heavy restrictions on their freedom. The Working Group underlines that Governments cannot accept detainees under such conditions without incurring serious violations of their obligations under international human rights law. 13 Ibid. See also report of the Special Rapporteur on torture and other cruel, inhuman or degrading treatment or punishment (A/60/316, para. 51).