New Zealand First leader Winston Peters continued his calls on Monday for United Future MP Peter Dunne to leave Parliament.
Mr Dunne resigned as a Government minister on Friday following an inquiry into the leaking of a report into the Government Communications Security Bureau in April this year.
The inquiry found communications between Mr Dunne and the journalist to whom the report was leaked that included references to the report's release. Peter Dunne insists he did not leak the report.
However, Mr Peters told Radio New Zealand's Morning Report programme on Monday he has always maintained that Mr Dunne leaked a number of documents.
Mr Peters said he has documents that prove Mr Dunne leaked the GCSB report and others and has lodged a complaint with police.
Police have confirmed that they have received a complaint from the New Zealand First leader about the leaking of the Kitteridge report to a Fairfax reporter.
A spokesperson said the complaint is being assessed to see if it meets the threshold for investigation.
Prime Minister John Key told Morning Report that he has already dealt with the matter. He said the document was sensitive, but not secret, and there was therefore little that could be done under the Crimes Act.
Govt accused of being politically bankrupt
Labour is accusing the Government of being politically bankrupt following the resignation of Mr Dunne as a minister.
Labour leader David Shearer said Prime Minister John Key should make Mr Dunne clear his name, otherwise it brings the stability of the Government into question. He said Mr Key is sitting on his hands because he does not want to lose Mr Dunne as a support partner.
The Prime Minister's office said on Sunday that Mr Dunne has paid a heavy price for his actions and that is where the matter lies.
A political commentator says Winston Peter's comments about Mr Dunne have succeeded in damaging the Prime Minister.
Matt McCarten, a former Alliance political strategist, said Mr Peters has changed the game and has turned focus of the issue on the prime minister.
He told Morning Report Mr Peters appears to have enough information to keep the subject going and this will eat away at the Government's credibility.
However, former ACT Party leader Richard Prebble said the general public don't care. He said political scandals fall into two categories and only those which directly affect the public will hurt the Government.
Mr Prebble said if Mr Peters wants to make ground for the next election, he needed to start talking about things that matter to people.