Michael Jones is listed on its website as vice-chairman, and former Labour MP Jonathan Hunt as honorary chairman.
Mr Hunt is a former Speaker of the House and a member of the Order of New Zealand. One of Parliament's longest-serving MPs, he was New Zealand's High Commissioner in London from 2005 to 2008.
Mr Hunt told the Herald yesterday he had informed former Labour list candidate Steven Ching of his resignation.
Mr Ching is a member of the CBRC, and was also involved in a new political party that was backed by Mr Chen.
The party was planning to contest this year's election but announced on Tuesday it was withdrawing.
Asked whether he had quit because of the charges laid against Mr Chen and Ms Wang, Mr Hunt said "probably", then refused to comment further.
Mr Hunt and Mr Jones have travelled with the CBRC to China, as recently as August. Photographs on the council's website show them sitting alongside Mr Chen and Ms Wang at official functions.
Photographs of a meeting between Mr Hunt and Mr Chen in March this year also feature on the website, alongside many photographs of Mr Jones, including one of him presenting an All Blacks jersey to Chinese billionaire Ke Xiping, who has a large shareholding in Natural Dairy.
There are also photographs of Mr Chen and Ms Wang meeting leading figures from the Maori Party.
Mr Jones said yesterday only a small part of his travel expenses in China were paid by Natural Dairy. He did not know what arrangements Mr Hunt had made, but most of his dealings with the CBRC had been through Mr Hunt.
The Herald was also invited to make the all-expenses-paid August trip to learn more about Natural Dairy's operations in China. It declined the invitation.
By late last night, Natural Dairy had not made any public statement about the charges.
Mr Jones said he was still hopeful his deal to supply Natural Dairy with hundreds of thousands of litres of Samoan noni juice would still go ahead.