A museum curator wants the Wildlife Act amended to include extinct native species, to help halt the trade in moa bones.
Moa specialist Mike Dickison of the Whanganui Regional Museum said TradeMe had not lived up to an agreement made a year ago to better manage the sale of moa bones.
It is legal to sell moa bones as long as they are not found on Department of Conservation land or do not form part of an archaeological site.
Dr Dickison said under the Wildlife Act, it was illegal to trade the body parts of living native species - and the same protection should be extended to extinct species.
TradeMe said it had introduced a system for investigating suspicious moa bone sales, but it had not yet been triggered.
TradeMe's head of trust and safety Jon Duffy said its new system was water-tight.
"We implemented a threshold which if triggered would engage our policing team to make inquiries with sellers of moa bones, and to date no one has tripped that threshold."
Mr Duffy said TradeMe had also created a "bones" page on its site so moa bone trades could be better tracked.