As the Prussian Palace made its grand opening of a museum on Wednesday, the debate on the return of artifacts plundered from abroad has reached its boiling point.

The Humboldt Forum will exhibit 20,000 treasures from Africa, Asia and Oceania, mostly from the former colonies.

Among the prized artifacts being displayed is the Benin Bronzes, which Nigeria’s ambassador to Germany, Yusuf Tuggar, has formally demanded their restitution.

The Benin Bronzes are hundreds of metal plaques and sculptures that decorated the royal palace of the Kingdom of Benin in the 16th and 18th centuries.

But they were looted by the British in the 19th century and are now scattered across European museums.

Tuggar said he had written “a formal letter” on behalf of his country to Gruetters and Chancellor Angela Merkel, but had received no reply.

The Prussian Cultural Heritage Foundation, which manages Berlin’s public museums, said “no official request for repatriation has been received”.

But said the foundation has been in contact with the relevant authorities in Nigeria to find ways to show the works in their country of origin and that repatriation had not been excluded.

Other European former colonial powers have in recent years started a process to consider the return of looted artifacts.

In November, the French senate unanimously voted to permanently return 27 African works to Benin and Senegal.