This paper explores how the general obligation of the Detaining Power to exercise the greatest leniency towards prisoners of war may be used in interpreting the provisions of the Third Geneva Convention of 1949 (GC III) related to the sanction regime to fulfil the obligation of humane treatment and to preserve the persons and honour of prisoners of war. The International Committee of the Red Cross updated Commentary on GC III is placed at the core of the arguments of this research.