Internet mogul Kim Dotcom is now thinking about suing New Zealand's spy agency for "illegal; surveillance." According to reports, the Independent Police Conduct Authority (IPCA) has found the police were justified in not pursuing any of the Government Communications Security Bureau (GCSB) officers for an illegal spying operation.

The New Zealand Greens had asked police in 2012 to investigate if GCSB agents had committed a crime after it was previously revealed that GCSB's surveillance against Kim Dotcom had been deemed "illegal."

The report by former Secretary of the Cabinet Rebecca Kitteridge was released last March 2013 said 56 spying operations were carried out illegally. The spying activities of the GCSB included those conducted on 88 individuals.

Reports said NZ Greens co-leader Russel Norman wrote a follow-up letter to the Commissioner of Police and requested to pursue all cases involving the illegal spying activities in the last ten years.

He said the spying operation against Dotcom was illegal because under New Zealand law, the GCSB was not allowed to conduct surveillance on the country's permanent residents.

However, the police said they will not be persecuting GCSB agents because they didn't have "criminal intent" despite technically breaking the law. The IPCA has backed this view.

In relation to the issue, Dotcom posted on Twitter that he was seriously considering suing the GCSB for illegal surveillance on July 17.

Meanwhile, Norman expressed his disappointment regarding the findings of the IPCA and claimed the legal system in New Zealand has a double standard. He said when individual citizens break the law, they immediately face prosecution unlike Prime Minister John Key's "spies."

Labour MP Grant Robinson said the IPCA findings will not do anything to restore the public's trust in the spying agency.

New Zealand Labour has previously asked Prime Minister John Key to admit that the country's spy agency has been trained by the U.S. National Security Agency to do mass surveillance. Documents published in a new book revealed that all agencies involved in the Five Eyes Network were trained to operate a sophisticated system that can sift through phone numbers, email addresses and online chat messages.

The documents based on new revelations by former NSA contractor and whistleblower Edward Snow appeared as part of journalist Glenn Greenwald's book No Place to Hide. One document contained an invitation to New Zealand's spy agency and other members of the Five Eyes network to "sniff it all, know it all, collect it all, process it all and exploit it all."

Mr Key has repeatedly denied of having known of any mass surveillance on Kiwis.