Questions are being raised about New Zealand's barely regulated ivory trade.

The Jane Goodall Institute believes New Zealand is contributing to the deaths of thousands of elephants and rhinos every year by failing to crack down on the trade.

Sunday marks World Elephant Day.

The current rules state the only ivory that can be traded is that imported either before a worldwide ban in 1989, or with Department of Conservation permission - but importers aren't required to provide evidence of an item's age or where it came from.

Ambassador Fiona Gordon says the rules need to be tighter.

"All these pieces are selling with absolutely no information about where they came from or when they were obtained. There is an international ban."

The Jane Goodall Institute estimates one elephant is killed for its ivory every 15 minutes. Ms Gordon says too many people are unaware of the practise.

"Thirty to 40-odd items of ivory are selling each month, and when they're going for thousands of dollars, it's quite lucrative… Our trade is completely unregulated."

New Zealand's most popular auction website Trade Me banned all ivory trade in 2014.

Ms Gordon says New Zealand is lagging behind other countries.

"It was quite a historic decision to close all global domestic ivory markets, but New Zealand has been very slow to close its own trade."

The Government in 2014 declined a request from Ms Gordon to toughen the rules, saying "given New Zealand's low volume of trade, the likely net conservation benefits of such a system would be negligible".

Last month an English migrant's antique piano was impounded because it had ivory keys.

A DoC spokesperson told NZME around 180 people a week have items confiscated at the airport.

Newshub.