The Chinese multi-millionaire named as donating $100,000 to the National Party says he is "disappointed" to have been dragged into the political furore engulfing party leader Simon Bridges.

Botany MP Jami-Lee Ross earlier this week claimed Yikun Zhang made the donation in either May or June this year.

That donation is now at the centre of claims by Ross about unlawful conduct by the party's leader Simon Bridge.

There is no suggestion that Zhang acted improperly in any way in relation to the donation.

Southland mayor Gary Tong is currently travelling with Zhang in China and told Newstalk ZB on Thursday the businessman was "very disappointed".

"The only comment he wants to make is that he is very disappointed, but I'm just very concerned for what's going on over there. Someone needs to step up and tell the truth."

Tong told Heather du Plessis-Allan that it is his understanding that Zhang did not donate the $100,000.

“Mr Ross needs to come out and actually put his cards on the table.”

Tong says that an association Zhang is the President of, which is for Chinese living outside of China, could have donated the money but he is not sure.

LISTEN TO GARY TONG TALK WITH HEATHER DU PLESSIS-ALLAN ABOVE