A French court stepped in on Wednesday to block the return to New Zealand of the mummified head of a Maori warrior held in a provincial museum since the 19th century.
The mayor of Rouen offered to return the tattooed head last week, but the Culture Ministry contested the plan, taking the case to the city's administrative court. The court upheld the ministry's appeal.
The ministry is concerned that such offers by individual museums could threaten its control over artifacts from other civilizations, such as ancient Egypt or Peru.
Culture Minister Christine Albanel has said the head is covered by rules designed to ensure that museum holdings remain intact. A decision could only be made after a recommendation by a scientific commission, she said.
Human remains from Africa or the South Pacific were often collected by 19th century ethnographers and many were taken to European museums.
Ambassador Sarah Dennis said New Zealand had a longstanding policy of trying to bring back human remains — but added that the decision was ultimately a French matter.
"The New Zealand approach is to go quietly ... and create confidence about what it is we're looking to do, how we do it and why," she told Reuters.
"This is something that is very important and profoundly felt in Maori culture."
In 2002, France agreed to return to South Africa the remains of Saartjie Baartman, a young woman dubbed the 'Hottentot Venus' and paraded as a freak show attraction in the 19th century.