The principle of postliminium, as a part of public international law, is a specific version of the maxim ex injuria jus non oritur, providing for the invalidity of all illegitimate acts that an occupant may have performed on a given territory after its recapture by the legitimate sovereign.
Therefore, if the occupant has appropriated and sold public or private property that may not legitimately be appropriated by a military occupant, the original owner may reclaim that property without payment of compensation.
The codification of large areas of international law have made postliminium to a great extent superfluous though.
[2] Woltag, J.-C., 'Postliminium' in Wolfrum, R. (ed) Max Planck Encyclopedia of Public International Law (Oxford University Press 2009).
*"Max Planck Encyclopedia of Public International Law".