The Louvre museum in Paris will return five ancient fresco fragments to Egypt, the French culture ministry has said.This is interesting because it sets a precedent for other artefacts (and possibly human remains), albeit only ones that were looted or stolen.
The Egyptians say the Louvre bought the Pharaonic steles in 2000 even though it knew they had been stolen in the 1980s.
In my view it only sets a precedent for human remains from other cultures. Archaeologists who dig up ancient British remains have as much claim to descent from those remains as anyone else. However, where indigenous remains from other cultures were looted without the permission of the indigenous people concerned, they should be returned.
In the case of artefacts from other cultures, if they were bought legitimately by the museum in which they reside, then the other country should buy them back. If they were not bought legitimately then they should be returned. In the case of the Elgin Marbles, they were removed when a foreign power was occupying Greece, and should be returned to Greece now that there is a suitable museum for them to reside in.