Winston Peters looks to take legal fight to Supreme Court

It's not over yet - former Deputy Prime Minister Winston Peters is now looking to take his legal fight over the leaking of his superannuation overpayment details to the Supreme Court.

Winston Peters.

The New Zealand First leader is seeking leave to appeal to the country’s highest court after his cases seeking damages were rejected in the High Court and Court of Appeal.

In the run up to the 2017 election, Peters revealed his superannuation had been overpaid - he'd made an error on the form and was being paid the single person's rate even though he had a partner.

Peters paid back the $18,000 he'd been overpaid.

Multiple news agencies had been tipped off to the overpayments and Peters has accused a wide range of people of being responsible, including former National Party ministers, senior public servants and recently, even political staff.

Peters' lawyer, Brian Henry, told the Court of Appeal his client did not know who had leaked his private information and wouldn't be able to find out.

Peters confirmed the bid to appeal to the Supreme Court but declined to comment further, claiming it would be sub judice.