Opposition MPs brandished copies of the police file on John Banks in parliament on Thursday but failed to corner the government over whether the ACT leader was fit to be a minister.
Police have released the file on their investigation into donations to Mr Banks' Auckland mayoral campaign, including evidence from internet piracy accused Kim Dotcom that at a meeting in June 2010 Mr Banks asked for a $50,000 donation to be split into $25,000 cheques so he wouldn't have to declare where they came from.
"He said to me `I want to help you Kim and I can help you more effectively if no one knows about this donation'," Mr Dotcom said in an affidavit.
Mr Banks declared the donations as anonymous and police concluded that while that was wrong there wasn't sufficient evidence to prosecute him under electoral law.
The file has given opposition MPs more ammunition to fire at the government because Mr Banks holds ministerial portfolios under a support agreement with National.
Labour's Trevor Mallard was told by Speaker Lockwood Smith he wasn't allowed to say Mr Banks had lied but got away with his next question to Prime Minister John Key.
"Is it his policy to allow people who lie and have been shown to lie to be members of his ministry," he asked.
Mr Key wasn't in parliament and Economic Development Minister Steven Joyce replied on his behalf: "I'm not answering a hypothetical situation".
Labour MPs tried to table the police file so it would become an official document of parliament but they were blocked by government members.
Outside parliament, Labour's deputy leader Grant Robertson said Mr Banks should be sacked.
"On May 1 this year John Key told parliament John Banks had given his chief of staff an assurance that he was not aware that Kim Dotcom had made the donation," he said.
"Yet sworn statements from Kim Dotcom, his bodyguard and his lawyer show that John Banks did know about the donation."