A wealthy Auckland businessman, whose links to the National Party led to a minister's resignation, also made a secret $15,000 donation to the Labour Party - and hosted a Cabinet minister at a lavish dinner in China.
The Labour Party has previously accused the Government of "cash for access" deals with Donghua Liu, who received citizenship after lobbying from National minister Maurice Williamson and whose hotel was later opened by Prime Minister John Key.
But the Herald can reveal Liu, 53, also paid $15,000 at a Labour Party auction in 2007 for a book signed by Helen Clark, the Prime Minister at the time, according to a party source.
The source said Liu also hosted Rick Barker, the then Internal Affairs Minister, at a dinner in his hometown of Chongqing.
Mr Barker, who is now a regional councillor in Hawkes Bay, confirmed he was a guest at the dinner and also visited Liu's cement company while on holiday in China. But he said he was not aware Liu was a Labour donor and he was not in China on official business as a minister.
"I went to China to catch up with some friends of mine, see some sights ... and I made a side trip to Chongqing - I had not been to the city before.
"I was in the city a short time. Mr Liu showed me his business and that night, I attended a dinner which seemed to be a dinner he had put on for all his staff."
However, Mr Barker could not remember how he came to be invited to visit Liu in Chongqing.
He said it was "probable" he also had dinner with Liu in New Zealand.
"I am trying to recall events of over seven years ago, so it's a little challenging. But it can't have been a regular event, because if it was I would recall that. In fact my contact with Liu fell away quite quickly."
Political donations made at fundraising auctions or dinners are not recorded individually, but the total amount raised is declared.
Mike Williams, Labour's president at the time, said he did not remember seeing Liu at any fundraisers he attended. "If he was a significant individual donor to the party, I would have probably known about it. But the name honestly doesn't ring a bell at all."
Liu, who has pleaded guilty to two domestic violence charges and is seeking to be discharged without conviction, was unable to be reached for comment.
At the time of the donation and dinner with Mr Barker, Liu had permanent residency - granted in 2005 by Labour's Associate Immigration Minister, Damien O'Connor, against official advice - but was not yet a New Zealand citizen.
The revelation that he later made a $15,000 donation to Labour comes after MPs attacked National for "cash for access" deals with donors.
Labour leader David Cunliffe said he was unaware that Liu was a donor to his party, but that would not change the criticism levelled at the National Government, "which was that a minister of the Crown involved himself in a police operational matter and it's also the case that both the Prime Minister and Minister of Immigration have been considering policy changes at the request of Mr Liu".
Mr Cunliffe doubted there was any connection between Liu's residency bid and his donation two years later.
Mr Williamson was forced to quit his ministerial portfolios last month after the Herald revealed he contacted police over the domestic violence charges against Liu, who was recorded as donating $22,000 to National and was a regular at party fundraisers. He also had a personal meeting with Immigration Minister Michael Woodhouse last year in an attempt to secure relaxed immigration rules for rich migrants.
New Zealand authorities are now investigating Liu's role as a witness in a bribery trial and subsequent citizenship application in New Zealand.
A Herald investigation revealed Liu gave cut-price real estate deals to a Chinese politician and received business favours in return. Liu said he was not charged in connection to the corruption case but gave evidence at the 2006 trial that led to a 13-year jail sentence for the political leader convicted of accepting bribes.
But his role as a witness has raised questions about his background in China and what was disclosed to New Zealand authorities when he was granted residency in 2005 and citizenship in 2010 - each time against the recommendation of officials.
Immigration New Zealand, the Department of Internal Affairs and the police have shared information on the case and the Herald understands Superintendent Hamish McCardle, the New Zealand police liaison officer based in Beijing, has been asked to check records in China.