An art expert is questioning whether an ancient Māori flute, or kō-au-au that has been sold at auction in Germany, was smuggled out of New Zealand.
John Perry, an art collector, was the director of Rotorua Museum for more than 20 years.
He said he used to be the kaitiaki of a similar flute during his time at the museum.
Mr Perry said the German auction house listed it as part of a collection previously owned by the Austrian artist Friedensreich Hundertwasser.
He says the flute fetched NZ$3,000 at auction.
Mr Perry said he suspected it was made of human bone, is several hundreds years old, and extremely rare.
"It's a very simple, beautiful, scared, tapu, object and it concerned me that perhaps it might've been exported illegally," he said.
Mr Perry said given the size of the kō-au-au, it would be relatively easy to smuggle overseas.
He said he requested a copy of its export documents from the auction house weeks ago, but he still hasn't heard back.
"People are exporting kauri logs, saying they're table tops and getting away with it, so to take a four-inch piece of bone out of the country would be a fairly easy thing to do."
Mr Perry said Polynesian and Māori artefacts are very sought after in Europe and generally command high prices.