Articles 120 and 121 of the Geneva Convention III Relative to the Treatment of Prisoners of War set out extensive and complete obligations with respect to recording the identity of those who are combatants in an International Armed Conflict, the cause of death and treatment of remains.
Article 120. The burial or cremation of a prisoner of war shall be preceded by a medical examination of the body with a view to confirming death and enabling a report to be made and, where necessary, establishing identity. The detaining authorities shall ensure that prisoners of war who have died in captivity are honourably buried and that their graves are respected, suitably maintained and marked so as to be found at any time. Bodies may be cremated only for imperative reasons of hygiene, on account of the religion of the deceased or in accordance with his express wish to this effect.
Article 121. Every death or serious injury of a prisoner of war caused or suspected to have been caused by a sentry, another prisoner of war, or any other person, as well as any death the cause of which is unknown, shall be immediately followed by an official enquiry by the Detaining Power. A communication on this subject shall be sent immediately to the Protecting Power. Statements shall be taken from witnesses, especially from those who are prisoners of war, and a report including such statements shall be forwarded to the Protecting Power. If the enquiry indicates the guilt of one or more persons, the Detaining Power shall take all measures for the prosecution of the person or persons responsible.
DISCUSSION PAPER: THE LEGAL OBLIGATION TO RECORD CIVILIAN CASUALTIES OF ARMED CONFLICT, pp. 7-8