A former director of the GCSB says there is mass collection of emails and communications in the Pacific, but the spy agency does not use material about New Zealanders collected inadvertently, Radio New Zealand reports.
The Green Party has laid a complaint with the Inspector-General of Intelligence and Security, saying the Government's electronic spy agency may have broken the law by spying on New Zealanders.
Investigative journalist Nicky Hager says the GCSB has intercepted communications from countries such as Fiji, Tonga, Vanuatu and Samoa, and even nations as small as Tuvalu, Nauru and Kiribati, and passed the information to the United States.
The Greens say New Zealanders who live, holiday or work in Pacific Islands could have had their data intercepted by the spy agency, and if that was the case, the law may have been broken.
Prime Minister John Key insists the Government's spy agency has acted within the law. He said the GCSB had given him a 100 percent categorical assurance that New Zealanders' information was not gathered other than in circumstances where the law would specifically allow it.
Sir Bruce Ferguson said he was 100 percent confident the GCSB was not acting illegally and that any intelligence-gathering involving Pacific Islands was to protect those countries as well as New Zealand.
He told Morning Report it was impossible to individualise data collection so the GCSB collects it all but discards items it cannot have.
"There will (from) time to time be inadvertent collection, mass collection of these things.
"But the Act specifies that they cannot then use that information, unless they've got specific reasons to use it against New Zealand they can't use it."
He said intelligence-gathering in the Pacific should not be seen as some nefarious attack on the Pacific islands when it is actually helping them and helping New Zealand.