It's understood the man was being questioned after the Wildlife Enforcement Group (WEG) group seized the ivory from a Napier address. Neither his age nor identity have been disclosed.
Buying and selling ivory in New Zealand is not prohibited but as soon as someone wants to import or export it, a permit is needed.
Jiang was caught after Customs officers intercepted two parcels at the international mail centre.
Both were addressed to his anglicised name "Kevin Jiang".
Customs officers raided his Mellons Bay property in October 2011 and found six items made from the tusks of endangered African elephants.
The police summary of facts stated the 56-year-old retiree had his son set up an account on auction website eBay.
From May 2010 to September 2011, Jiang was a prolific online trader and bought 299 items, including objects made of silver, bone china and ivory.
Jiang said he had sold two ivory items to people in China through a website because they "were not of artistic value".
During an interview with authorities, Jiang admitted bidding on and buying ivory items and sending them back to China.
He knew trading in ivory was restricted in China but did not know there were rules in New Zealand as well.
He told police he knew elephants were being killed for their ivory but thought it would be a good investment because they would increase in value.
Importing ivory into New Zealand is prohibited without a permit after New Zealand became one of the 175 countries to ratify the Convention on International Trade in Endangered Species of Wild Flora and Fauna.
As well as elephants, the convention also covers 5000 species of other animals and 29,000 species of plants.