Part VIII : Execution of the convention #Section II : Organization of control - Art. 86.
Art. 86. The High Contracting Parties recognize that a guarantee of the regular application of the present Convention will be found in the possibility of collaboration between the protecting Powers charged with the protection of the interests of the belligerents; in this connexion, the protecting Powers may, apart from their diplomatic personnel, appoint delegates from among their own nationals or the nationals of other neutral Powers. The appointment of these delegates shall be subject to the approval of the belligerent with whom they are to carry out their mission.
The representatives of the protecting Power or their recognized delegates shall be authorized to proceed to any place, without exception, where prisoners of war are interned. They shall have access to all premises occupied by prisoners and may hold conversation with prisoners, as a general rule without witnesses, either personally or through the intermediary of interpreters.
Belligerents shall facilitate as much as possible the task of the representatives or recognized delegates of the protecting Power. The military authorities shall be informed of their visits.
Belligerents may mutually agree to allow persons of the prisoners own nationality to participate in the tours of inspection.