The Independent Police Conduct Authority has found police were justified in not prosecuting officers of the Government Communications Security Bureau for alleged illegal spying.
The Authority said police based their decision on the grounds there was an absence of criminal intent.
It said the decision not to prosecute was based squarely on an opinion provided by the Solicitor-General and they were quite entitled to rely upon this advice.
The Green Party had complained to the IPCA alleging neglect of duty by police in relation to their investigation into the GCSB's operations.
The police had carried out their own investigation into a complaint about the Bureau's surveillance of Kim Dotcom and an associate, that had been found to be illegal.
They found that while the spy agency staff did technically break the law, they didn't have criminal intent.
A report by the then Secretary of Cabinet, Rebecca Kitteridge, prompted by the illegal operation against the internet entrepreneur Kim Dotcom, found 56 possible operations in total, involving 88 individuals, where the GCSB may have spied on New Zealanders illegally.
Police have put out a statement saying they now consider the matter closed.