Police have turned down a request for an investigation into the leaking of a highly sensitive report into the Government's spy agency.
New Zealand First laid a complaint with the police in early June this year after independent MP Peter Dunne refused to fully co-operate with an inquiry into who leaked the report into the Government Communications Security Bureau to a Fairfax journalist.
New Zealand First said it had documents that proved Mr Dunne was responsible for the leak which the party described as a serious breach of national security. Mr Dunne denies leaking the report.
Assistant Commissioner Malcolm Burgess said on Tuesday that police are satisfied that no offence has been committed. Mr Burgess said unless additional information was provided, further investigation would not provide evidence leading to a prosecution.
New Zealand First leader Winston Peters said police had asked the party to provide further information just last week.
"Both verbally and in writing we said their request for more information would be met. We were assembling it to send it downtown. So two days after we met they'd made a decision, which is somewhat surprising."
Mr Peters said police have a different view than that of New Zealand First on the matter of national security.