A portrait of Captain Cook by John Webber circa 1780 (Te Papa)

The source said Mr Forster-Bell was "trying to impress Sir Christopher", who donates to the National Party.

Sir Christopher has confirmed he asked Mr Foster-Bell to push the Captain Cook name change. He said he'd been a member of the National Party for 65 years, "and I donate. I give a bit, but so do a lot people."

Sir Christopher said he knew Prime Minister John Key, and had also pushed the name change with him.

"I've got in touch with him via email. I haven't got to the point of having a chat to him. I have been in touch with the Prime Minister and various ministers over the years."

Mr Foster-Bell declined to comment on the matter. He has been under pressure to explain why 12 staff have left his two-person office in the past three years and why he racked up over $60,000 in taxpayer-funded travel, despite being a Wellington-based backbencher.