Millionaire businessman Donghua Liu has hired a high-profile Queen's Counsel to deal with any legal action from the Labour Party.
Aucklander Paul Davison, QC, is heading a team of advisers for Liu reviewing the property developer's records following the comments of David Cunliffe this week.
The Weekend Herald understands this includes more than 30 photographs taken over 18 months linking Liu to Labour, including a fundraiser at an Auckland restaurant and a trip to China, where he hosted a Cabinet minister in 2007.
Liu is also seeking to retrieve financial records held in China.
Labour Party general secretary Tim Barnett confirmed that a lawyer for the party had contacted Liu's legal counsel but was yet to receive a substantive reply.
"The Labour Party has no dispute with Mr Liu because we have seen no evidence that he has published false information about us."
A spokesman for Mr Cunliffe declined to comment.
Mr Davison, most recently in the limelight for representing Kim Dotcom in multiple court proceedings, confirmed a letter from Labour's lawyer had been considered and responded to.
"Now we are waiting for a response."
The potential legal stoush comes after 53-year-old Liu has been at the centre of political sagas with both parties.
These include the resignation of Maurice Williamson as a minister after the Herald revealed that he intervened in a prosecution involving Liu.
The Herald last week revealed Mr Cunliffe wrote a letter for Liu's residency application, despite previous denials.
Earlier this week, the Labour Party leader said he was looking for an apology and looking at his "options" after Liu clarified a statement to say he did not pay $100,000 for one bottle of wine as previously reported.
Liu said: "I did say I made a contribution of close to $100,000 and that is my closing comment in my statement ... that is how much I believe I have donated in total to Labour and some of their MPs during their last term in Government."
He said the figure was the total payments to Labour and its politicians, which included the wine auctions, a $2000 donation to the Hawkes Bay Rowing Club, the Yangtze River trip and anonymous donations to MPs.
"I have no reason to inflate this number. It's as best as I can remember," said Liu.
The Labour Party said the Yangtze River trip with Rick Barker, the Minister of Internal Affairs at the time, and the $2000 donation to the rowing club in 2007 could not be considered as financial support to the party.
Mr Cunliffe said the clarification vindicated the position taken by Labour to "challenge him and those reporting on the claim to produce the evidence".
He also said the $50,000 figure quoted by Liu for the Yangtze River trip was "ludicrous".