International law on shipwreck salvage rights has not yet stabilised and usually requires case-by-case litigation. A common example of this is litigation between a commercial salvage company and the flag state (nation) of the recovered shipwreck.
Considering that many shipwrecks with rich cargoes are from the Age of Discovery/Exploitation: Has there ever been a salvage dispute between an ex-colony and its former colonial master?
For example, a shipwreck that was carrying gold and silver from Mexico to Spain being litigated by Mexico as "The stolen wealth of the Mexican people" versus Spain's "It was our ship and you were our colony when it sank".
This scenario needn't be limited to colonies or shipwrecks in the Americas.