National Party leader John Key has defended the time spent on the 'tea tape' investigation as police demand that four news organisations, including Radio New Zealand, hand over material relating to the recording.
Mr Key laid a complaint on Monday that his conversation with ACT's Epsom candidate John Banks at a photo opportunity in an Auckland cafe last week was illegally recorded.
Campaigning in Whangarei on Thursday, Mr Key said any police action following the complaint he laid was out of his hands, as the police act independently.
When asked whether his complaint was a good use of police resources, Mr Key said National had lowered the crime rate across the country so police had a little bit of spare time and this was an important issue.
Mr Key said he felt strongly about the matter. "We've got to have ethics in the way that the media in this country operate and I believe that wasn't on display last Friday."
Police Association president Greg O'Connor said Mr Key might want to re-think his statement about police time.
"This thing is about pure politics," he said. "Police have always got something to do."
Mr O'Connor said once a complaint was made police had to investigate it properly.
RNZ refuses to hand over material
Officers working on the case have asked Radio New Zealand for unpublished material relating to interviews it conducted with the cameraman who made the recording and gave it to the Herald on Sunday newspaper.
Radio New Zealand head of news Don Rood said he has refused to hand over any material gathered by news staff.
"We'll be calling our lawyers in and suggesting that it goes to court because we're not prepared to back down over what to us is a basic tenet of a good public service broadcaster."
He said the organisation will always protect its sources and the right to gather and report news in the public interest.
A police spokesperson said that four media organisations were being asked to hand over information and police were following standard procedures in obtaining material from the media under a search warrant.
TVNZ and TV3 have also been asked to give information to the police while the fourth media organisation has not yet been identified.
The editor of the Herald on Sunday, Bryce Johns, said the paper had not yet been approached by the police.
Mr Rood says the police have told him they will get a search warrant and execute it on Thursday or Friday.
Radio New Zealand says it does not have a copy of the original tape at the centre of the complaint.
Cameraman takes legal action
The lawyer for Bradley Ambrose, the cameraman at the centre of the controversy, said he had on Thursday filed civil proceedings in the High Court in Auckland.
The Mr Ambrose is seeking a ruling the that conversation between the politicians was not a private one.
Lawyer Ron Mansfield says the legal action is being taken because of the allegations being made publicly against his client in alleging his conduct was criminal or unethical.
He said Mr Ambrose's reputation is important because journalism is his sole source of income.
Saga becoming 'extreme'
Labour Party leader Phil Goff said the investigation was a waste of valuable police time and looked to him like an effort by Mr Key to gag the media.
"It's going to ridiculous lengths. Why doesn't he just come clean, say what he said - he claims it was bland - and let the public know."
Mr Goff said the public would then make their own judgement.
Green Party co-leader Metiria Turei believes the tea tape saga has got out of control, and says it does not justify police raids on media organisations.
"The police are not even looking for information about the tape, they're looking for other kinds of information related to it," she said. "It's just gotten completely extreme."
Ms Turei says John Key should withdraw his police complaint, and put an end to this saga which she says is derailing the election campaign.