A Dutch museum with Crimean gold and artifacts on loan from Ukraine is unsure where to return the art now that Russia has annexed the region, according to The Art Newspaper.

The archeological museum at the University of Amsterdam asked Dutch authorities to issue guidance on what to do with the artifacts when its temporary exhibit closes this summer.

“The Allard Pierson Museum considers it extremely important to exercise care in this situation,” a University of Amsterdam spokesperson told The Art Newspaper. “Given the complexity of the issue, the manner in which the objects will be returned is currently being investigated by the legal advisers of the university.”

Five Ukrainian museums loaned ancient jewelry and armor to a museum in Germany, and then to the University of Amsterdam. The exhibit was set to close in May, but has been extended through June.

In addition to the gold, the collection features Chinese lacquer boxes found at a Crimean burial sight, according to paper.

Image via the Allard Pierson Museum