Deputy Prime Minister Winston Peters has spoken to RNZ about his decision to appeal a high court decision.
Peters is appealing a High Court judgement against him, saying he now knows who leaked his superannuation details in the lead-up to the 2017 election.
"It's about the privacy of anyone who has had their rights breached in this manner, it's a foundation stone of our society and of democracy and without it we look forward to a very bleak future as a country, so it's a very serious issue and it's worth defending," he said.
He said he would not be commenting further on where the leak came from, for now.
"You've got my statement and that's all about I can say on it," he said.
The original court case cost taxpayers more than $1 million in defending those he accused.
He was overpaid nearly $18,000 over seven years, after he did not fill out a section of his application form that asked whether he had a partner.
He repaid it, and launched legal action, taking State Services Commissioner Peter Hughes, former Ministry of Social Development head Brendan Boyle and former National Party ministers Anne Tolley and Paula Bennett to court, claiming they had breached his privacy.
Peters dismissed the suggestion the public would not stomach any more money coming from the taxpayers' coffers.
"The point is it's a matter of law and the law be applied properly."
He told RNZ it "may be" that going back to court would potentially plague him during the election this year, but said a "matter like privacy in our society is critical".
"Without it - then I can describe the kind of society you're going to see - and it will be awful."
Peters said he could not give a timeline of the process and could not rule out the possibility it would be during the election.
"No one in my position or in this sort of this position has any control over the court process, any sort of insinuation like that would be wrong because it's in the hands of others," he said.
He also would not confirm whether or not he would go public with who he believed leaked his overpayment if the court process failed again.
The case was heard last November in the High Court in Auckland.
Justice Venning said Peters' claim failed because he could not establish that any of the defendants were responsible for the leak.
The judgement was released last month.
In an earlier statement, Peters said it had "always been known that this case was leaked. Leaked with an intent to do harm. Leaked for a purpose."
"Within government and the Civil Service no less than 42 individuals knew about this one case.
"The matter was resolved before it got the attention of Ministers via the Ministry of Social Development.
"So what was their investigation, internal inquiry and internal disclosure about, was it to say that we have this case that has been resolved, but we want you Ministers to know about it, but why?"
Peters said his was the only case where someone had made a mistake on their superannuation application to have made headlines.
He said the Prime Minister at the time, Bill English, was on record saying the information should never have been disclosed.