A/HRC/10/44/Add.2 page 3 should be used only in exceptional circumstances or when absolutely necessary for criminal investigation purposes. In all cases, solitary confinement should be used for the shortest period of time. The Special Rapporteur is encouraged by the establishment of an inter-ministerial working group to investigate alleged Central Intelligence Agency (CIA) rendition flights operating through Denmark and Greenland, and strongly encouraged the inclusion of independent experts and civil society in a fully transparent process. The Special Rapporteur expressed concerned about recent plans to employ diplomatic assurances to return suspected terrorists to countries known for their practice of torture.