The Government is being asked to stop the sale of looted moa bones on online sites such as Trade Me.
Mike Dickison, the curator of natural history at the Whanganui Regional Museum, told Saturday Morning a loophole in the law meant selling the bones was not illegal.
Mr Dickison said thousands of moa bones were being looted from archaeological sites around New Zealand and, once they were moved, all scientific data was lost.
He said trading in moa bones was not covered by the Protected Objects Act or the Wildlife Act but the appropriate minister could extend the Wildlife Act to cover it.
"Things are really starting to hot up on Trade Me and people seem to be looting particular archaeological sites," he said.
"Some buyers are selling thousands of bones. A lot of the lots are being bought by traders who split them up and sell them on again."
Mr Dickison said he and a number of other curators want the loophole that allows the sales closed up.
He said the bones were not supposed to be taken from archaeological sites or conservation land and, when asked, people who were selling them said they had "had them for ages, been in the family".