New Zealand Inspector-General of Intelligence and Security Cheryl Gwyn on Thursday launched an inquiry into complaints that a spy agency, the Government Communications Security Bureau (GCSB), intercepted the communications of the country's citizens in the South Pacific.
In a statement, Gwyn said the complaints and other public allegations raise wider questions regarding the collection, retention, and sharing of communications data.
"I will be addressing the specific complaints that I have received, in accordance with the Inspector-General of Intelligence and Security Act 1996," she said.
"But there is also a clear need to provide as much factual information to the complainants, and to the wider public, as is possible."
Documents released by United States National Security Agency (NSA) whistleblower Edward Snowden revealed last week that the GCSB had collected the email, phone, and social media communications of its Pacific neighbours.
It also shared these with the NSA and other Five Eyes spy alliance members.
The GCSB delivered "full take" collection, allowing the NSA to use its XKeyscore search engine to trawl the communications content and metadata for intelligence.
It appears the communications of New Zealand citizens were included in the mass interception, something that is illegal without a warrant.
New Zealand Prime Minister John Key has said that GCSB's activities are legal, but refused to comment on the specifics of the allegations.
Gwyn said she would not only investigate the complaints, but also bring forward and expand her review and audit of GCSB procedures and compliance systems.
"That review program operates at a systemic level and doesn't, of course, scrutinise or second guess every day-to-day aspect of the GCSB's operations. What it does allow for, as in this instance, is a focused review of a particular area of GCSB or New Zealand Security Intelligence Service practice," she said.
"I have today notified the acting director of the GCSB of my inquiry and of my intention in this inquiry to provide as much information to the public on my findings as I can, withholding only that information that cannot be disclosed without endangering national security.
"The director has assured me of the bureau's full cooperation."