A French court has blocked a museum's efforts to return the mummified head of a Maori warrior to New Zealand.
The tattooed relic was acquired by a museum in the city of Rouen in 1875.
The museum offered to return the head to New Zealand, citing the need to bring closure to the "hateful trafficking of another era".
However, France's culture ministry appealed against the move, citing fears it could set a precedent leading to the return of other treasures from abroad.
"Today it's a Maori head, but tomorrow it could be a mummy in the Louvre," Olivier Henrard, legal adviser to the culture ministry, told the AP news agency.
French museums house thousands of valuable artefacts taken from civilisations in Africa, Asia and South America.
A statement by culture minister Christine Albanel said Rouen's natural history museum had not followed procedure in arranging the relic's return.
"Such a decision requires the advice of a scientific committee, whose role is to verify that there is no unjustified damage to national heritage," the statement said.
A court in Rouen has now ruled that the head must remain in France until a further decision is made at the end of the year.
The mummified head was due to have been handed over to a representative of New Zealand's Maori community at a ceremony in Rouen this week.
A Maori envoy and Rouen's mayor (left) had tried to transfer the head
The city's mayor, Pierre Albertini, wrote in his blog that this "ethical gesture" was "based on the respect for world cultures and the dignity of every human being".
The heads of slain Maori warriors, marked in distinctive tattoos, were sometimes kept as trophies by their rivals.
The arrival of Europeans in New Zealand sparked a trade in which the mummified heads would be exchanged for valuable goods.
According to Rouen museum officials quoted by the AP news agency, such was the demand for the heads that some Maori men were killed simply for their tattoos.
New Zealand officials said they were hopeful the head would eventually be returned but the decision ultimately rested with the French.
"The way we will be successful is just quietly maintaining cordial relations with the institutions," Paul Brewer of the Te Papa Tongarewa Museum told the AFP news agency.
France in 2002 repatriated the remains of Saartjie Baartman, a South African woman who was pejoratively branded the "Hottentot Venus", brought to Europe and paraded as an exotic curiousity in the 19th Century.