Winston Peters has used parliamentary privilege to accuse former National Party staffer Rachel Morton of leaking his superannuation details in 2017 - allegations she has "categorically" denied.
Peters used parliamentary privilege on Wednesday to purportedly "outline the truth" about the leak in 2017, alleging that Morton passed on the information to former minister Anne Tolley who he said then passed it on to Paula Bennett.
Peters took Tolley, Bennett and a number of Government officials to court last November over the leaking to the media before the 2017 election of the information, which contained details about his superannuation overpayment.
Using parliamentary privilege, Peters accused Morton of passing the information to her ex-partner, ACT leader David Seymour - an allegation they both deny.
"All it took was for that private information to fall into the hands of David Seymour who craved media attention but couldn't claim the limelight because that would have placed the spotlight on Rachel Morton, his source," Peters said.
"This is what dirty politics looks like. That's why I have fought this case on principle at a huge cost - the principle of privacy. The collusion between the National Party, ACT, and these grubby figures in and around politics is what turns people off politics."
Morton, who was former National Party leader Simon Bridges' press secretary, denied the allegations in a tweet on Wednesday.
"The claims made by Winston Peters about me today are categorically not true."
Seymour also denied the allegations and blasted Peters in Parliament for using parliamentary privilege to make the claims.
"There is a quid pro quo for having the privilege of standing in this House. That is to use parliamentary privilege judiciously, with class and with discipline for the public good," Seymour said.
"What did we hear in the disgraceful, sleazy, innuendo-riddled speech from Winston Peters in this general debate today? Winston Peters told the House that the reason his inability to fill out his own superannuation form got into the public domain was because my then-partner told me and I told Jordan Williams.
"That is categorically untrue," Seymour said. "I want to tell the House none of that happened and the fact that Winston Peters is prepared to say it using the privilege of this House but he's not prepared to say it out there... he's not prepared to say it at all."
Seymour got kicked out of Parliament by House Speaker Trevor Mallard for labelling Peters a liar during his speech - but the Speaker allowed him to come back in if he withdrew and apologised, which he did.
Jordan Williams, executive director of the Taxpayers' Union, has denied the claims raised by Peters.
"Winston's claim that I was somehow involved in the leak of his superannuation scandal is, sadly, pure fantasy. I was not involved in any way," he said in a statement.
Peters has been ordered to pay nearly $320,000 in costs after a judge said he failed to pin the privacy breach on those who he took to court.
Following a two-week hearing, Justice Venning found that although Peters' privacy had been breached, he had failed to establish that any of the named defendants were responsible for the leak.
The action was taken against State Services Commissioner Peter Hughes, former Ministry of Social Development head Brendan Boyle and former National Party ministers Anne Tolley and Paula Bennett.
Peters has appealed the High Court's judgement.
Peters also faced backlash in Parliament over allegations he directed Antarctica NZ to replace Finance Minister Grant Robertson on a trip to Antarctica with his wealthy friends Bee Lin Chew and her daughter Su Arn Kwek - at the taxpayers' expense.
Emails released to RNZ, then Newshub, show Ministry of Foreign Affairs and Trade officials confirming there was only one seat and that if two seats had to be made available, other events would need to be cut.
Antarctica NZ told Newshub they made adjustments and didn't need to cut funding. Peters claimed he was attempting to help raise money - but none has been donated.
Peters called it a "racist" attack.
Prime Minister Jacinda Ardern said she understood Chew and Kwek visited in relation to the Scott Base rebuild and that the Government is trying to secure philanthropic funds.
Seymour said the Government would not seek philanthropic funds for Scott Base without going through a proper process.
"These are not the standards New Zealanders are entitled to demand from their Government. If the Prime Minister cannot uphold these standards from her ministers, we should get a new one."