Geneva Convention (IV): Relative to the Protection of Civilian Persons, Part III, Section 4, Chapter XII
Each interned person shall be released by the Detaining Power as soon as the reasons which necessitated his internment no longer exist.
The Parties to the conflict shall, moreover, endeavour during the course of hostilities, to conclude agreements for the release, the repatriation, the return to places of residence or the accommodation in a neutral country of certain classes of internees, in particular children, pregnant women and mothers with infants and young children, wounded and sick, and internees who have been detained for a long time.
Internment shall cease as soon as possible after the close of hostilities.
Internees, in the territory of a Party to the conflict, against whom penal proceedings are pending for offences not exclusively subject to disciplinary penalties, may be detained until the close of such proceedings and, if circumstances require, until the completion of the penalty. The same shall apply to internees who have been previously sentenced to a punishment depriving them of liberty.
By agreement between the Detaining Power and the Powers concerned, committees may be set up after the close of hostilities, or of the occupation of territories, to search for dispersed internees.
The High Contracting Parties shall endeavour, upon the close of hostilities or occupation, to ensure the return of all internees to their last place of residence, or to facilitate their repatriation.
The Detaining Power shall bear the expense of returning released internees to the places where they were residing when interned, or, if it took them into custody while they were in transit or on the high seas, the cost of completing their journey or of their return to their point of departure.
Where a Detaining Power refuses permission to reside in its territory to a released internee who previously had his permanent domicile therein, such Detaining Power shall pay the cost of the said internee's repatriation. If, however, the internee elects to return to his country on his own responsibility or in obedience to the Government of the Power to which he owes allegiance, the Detaining Power need not pay the expenses of his journey beyond the point of his departure from its territory. The Detaining Power need not pay the costs of repatriation of an internee who was interned at his own request.
If internees are transferred in accordance with Article 45, the transferring and receiving Powers shall agree on the portion of the above costs to be borne by each.
The foregoing shall not prejudice such special agreements as may be concluded between Parties to the conflict concerning the exchange and repatriation of their nationals in enemy hands.