Any person subject to this code who, while in the hands of the enemy in time of war:
(1) for the purpose of securing favorable treatment by his captors acts without proper authority in a manner contrary to law, custom, or regulation, to the detriment of others of whatever nationality held by the enemy as civilian or military prisoners; or
(2) while in a position of authority over such persons maltreats them without justifiable cause; shall be punished as a court-martial may direct.