An authority on taonga Māori and the Kaihautū at Te Papa says significant treasures should not be allowed to leave New Zealand and when they are taken illegally, the museum is usually only told when it is too late.
Arapata Hakiwai, who is also creating a database on taonga in overseas museums for the Māori Centre of Research Excellence, said significant treasures should not leave New Zealand.
And Mr Hakiwai said when paintings have left the New Zealand, under what he describes as questionable circumstances, the country has lost a considerable amount of its cultural heritage.
"Significant treasures like Goldies and Lindauers shouldn't leave our shores and that many of our taonga have left New Zealand under dubious circumstances and illegally ... probably the most famous one was the Motunui Pātaka Panels, so it's how we can protect [them] and I think there is an issue there of how we actually enforce that as well."
Arapata Hakiwai is critical of the Protected Objects Act (1975). He said there was a process in place to stop taonga being taken overseas illegally, but how that had been enforced had always been an issue.
"That is one area where usually when we've been informed it's too late."
But Mr Hakiwai does believe that taonga should be able to tour overseas as part of an exhibition.
"Having said that there is great benefit in exhibitions like the Te Māori exhibition and the exhibition that is travelling around Berlin which helps to promote the culture, with agreement from iwi and tribes to take our treasures overseas.