The Green Party has laid a complaint with police over the government spy agency's illegal surveillance of internet mogul Kim Dotcom.

A report into illegal spying by the Government Communications Security Bureau (GCSB) was released on Thursday.

It concluded the police and the GCSB were confused about Dotcom's status as a New Zealand resident, hadn't understood the implications of a 2009 immigration law change and, without checking, went ahead and spied on Dotcom in December and through to January 20 when he was arrested on allegations of internet piracy.

The GCSB is forbidden by law to spy on citizens and residents.

Opposition parties say the investigation was a whitewash, but Prime Minister John Key has ruled out an independent inquiry.

Green Party co-leader Russel Norman has asked police to investigate whether the GCSB breached the Crimes Act.

He says it appears they have breached a section banning interception of private communications - the same law Mr Key alleged cameraman Bradley Ambrose breached with the secret teapot tape recording of his cafe conversation with ACT leader John Banks last year.

Mr Key said he called in the police then as a "matter of principle".

Dr Norman says if Mr Key feels so strongly about privacy rights, he should support the police in investigating the GCSB.

"When he was taped in a public cafe by a media person discussing matters of public interest, Mr Key kicked up an almighty fuss and had police raid media outlets to make sure the tape wasn't released," Dr Norman said.

"The seriousness of the concerted and purposeful spying on private persons by government spies is orders of magnitude greater than the teapot tapes ever were."

Paul Davison QC, Dotcom's senior lawyer, says the report left many questions unanswered.

"We are far shy of receiving the level of detail we require and we are not satisfied the material gathered was limited to Dotcom's movements," he told Radio New Zealand.

The report says the surveillance was "largely" about Dotcom's movements before the police raided his Auckland mansion and Mr Davison wants to know what else was gathered.