Related Rule
New Zealand
Practice Relating to Rule 128. Release and Return of Persons Deprived of Their Liberty
New Zealand’s Military Manual (1992) provides: “Prisoners of war must be released and repatriated without delay after the cessation of active hostilities.” 
New Zealand, Interim Law of Armed Conflict Manual, DM 112, New Zealand Defence Force, Headquarters, Directorate of Legal Services, Wellington, November 1992, § 910.
The manual further states: “Unjustifiable delay in repatriating prisoners of war or civilians [is a grave breach when committed wilfully and in violation of the Conventions and Protocol]”. 
New Zealand, Interim Law of Armed Conflict Manual, DM 112, New Zealand Defence Force, Headquarters, Directorate of Legal Services, Wellington, November 1992, § 1703(4).
The manual also states:
935. Parties to the conflict are to repatriate, regardless of rank or number, all seriously wounded and sick when fit to travel and, when possible, agreements should be made between the parties, with the cooperation of neutral states, for the detention of such persons in neutral territory pending such repatriation. …
1133. Interned persons must be released by the Detaining Power as soon as the reasons which necessitated internment cease to exist. Internment must also cease as soon as possible after the end of hostilities but internees, who are in the territory of a belligerent and who are undergoing a sentence of confinement or against whom judicial proceedings … are pending, may be detained until the end of the proceedings or, as the case requires, of the sentence. Each State which is a party to the [1949 Geneva Convention IV] must endeavour, at the end of hostilities or of the occupation, to ensure the return of all internees to their last place of residence, or at least to facilitate their repatriation. 
New Zealand, Interim Law of Armed Conflict Manual, DM 112, New Zealand Defence Force, Headquarters, Directorate of Legal Services, Wellington, November 1992, §§ 935 and 1133.
New Zealand’s Geneva Conventions Act (1958), as amended in 1987, provides:
Any person who in New Zealand or elsewhere commits, or aids or abets or procures the commission by another person of, a grave breach … of [the 1977 Additional Protocol I] is guilty of an indictable offence. 
New Zealand, Geneva Conventions Act, 1958, as amended in 1987, Section 3(1).
New Zealand’s Military Manual (1992) provides that, in both international and non-international armed conflicts, the detaining authority is obliged to take such steps as are necessary to ensure the safety of released detainees. 
New Zealand, Interim Law of Armed Conflict Manual, DM 112, New Zealand Defence Force, Headquarters, Directorate of Legal Services, Wellington, November 1992, § 1814.
The manual also provides that prisoners of war are to be fed and provided with sufficient provisions if released. 
New Zealand, Interim Law of Armed Conflict Manual, DM 112, New Zealand Defence Force, Headquarters, Directorate of Legal Services, Wellington, November 1992, § 919.