Dr Dickison said anyone who found an archaeological site had to tell Heritage NZ. And, under the Heritage New Zealand Pouhere Taonga Act, it was unlawful to modify or destroy an archaeological site without prior authority.
Because the bones on Trade Me appeared to be broken, split, burned and spread among dog bones, he said they were clearly from an archaeological site.
"You can't just dig stuff up and sell it for pocket money," Dr Dickison said.
Moa bones are also classed as a protected object, which cannot be sent overseas without a permit.
In the questions under one listing, a buyer asked the lister about postage to Australia.
That buyer won the auction, Dr Dickison said.
"So those bones are are going to be shipped to Australia. He's not an amateur, he should know the law."
The moa-bone trade has long been a worry among museums and scientists.
"People [are] excavating archaeological sites and flogging things on Trade Me for actually not much money and in the process these hundreds-of years-old sites are being destroyed. That just seems wrong in so many ways," Dr Dickison said.
He said curators followed moa-bone listings on Trade Me and had compiled a record. The lister had confirmed on previous listings that some bones had come from Kaupokonui Beach, in South Taranaki, he said. "That's one of the most famous archaeological sites in New Zealand."
Heritage NZ says an archaeological site is a place associated with pre-1900 activity where there may be evidence relating to New Zealand's history, and it has been in discussions with Trade Me regarding the online sale of archaeological items.
Heritage NZ spokesman Jamie Douglas said: "There is legislation that covers the protection, ownership and distribution of archaeological material, which is important to remind all members of the public about.
"Raising awareness of the significance of archaeology will help prevent any potential unlawful modification or destruction of archaeological sites for financial gain."
Dr Dickison said a quick fix would be to put the burden on sellers to prove the legality of how they got the bones.
"We could shut the trade down tomorrow."
Longer term, there was an opportunity to stop the trade through legislation or reclassification of moa bones.
Dr Dickison hopes to advance his case at next week's meeting with Trade Me. "I want all of us to come up with a policy that works better. We'd hope they do the right thing."
Trade Me head of trust and safety Jon Duffy confirmed Tuesday's meeting with curators, Te Papa and government departments.
He said Trade Me was willing to co-operate.
"We don't want any bone listing on the site that may have been procured through an offence."
