A security expert says recommendations from a review of intelligence legislation could lead to the most significant reform of the sector in decades.
The 274-page report, by former Solicitor-General Sir Terence Arnold and prominent Māori lawyer Matanuku Mahuika, contains 52 recommendations for improving the Government Communications Security Bureau (GCSB) and the Security Intelligence Service (SIS).
Refocusing their work to include internal threats to security and removing a distinction between warrants for spying on New Zealanders and non-New Zealanders are among the recommendations.
Intelligence consultant Paul Buchanan said the definition of national security threat had shifted in the review.
"That includes threats that undermine the democracy from within, as well as external threats.
"That's significant because it allows the intelligence community to look a lot closer at internal threats, and integrates them even better - so civil libertarians are going to have cause for concern."
But he said the other recommendations - to overhaul Parliament's Intelligence and Security Committee and remove the prime minister - would bolster oversight.
"They're expanding the range of the powers of both the Inspector-General of Intelligence and Security and the Parliamentary Committee on Intelligence and Security, which up until now has been toothless. This review recommends giving that committee teeth and more importantly, independence from the government of the day.
"They're recommending expanding the membership, giving them a staff so they don't depend on the government and keeping the prime minister and the leader of opposition off the committee, because they say the committee has always lacked not only teeth, but also independence from the government."
The report also put the case for reforming the Customs and Excise Act 2018 to enable Customs to share information for counterterrorism purposes.
Other potential changes would reshape the culture of the organisations, he said.
"One of the things they're trying to do is they've altered the 'charter' of the intelligence agencies' sharing of information from 'need to know' to 'need to share'. And that's remarkable, because what we did find out with the royal commission on the Christchurch massacre, is that the police and the SIS and other agencies were not sharing information - they were doing what is known as stovepiping or siloing, keeping it to themselves. This review says no - the bias should be in favour of sharing."
Immigration lawyer and former minister Matt Robson has previously called for better select committee monitoring of how intelligence services work, especially when it comes to immigration intelligence.
A decision in a Chinese couple's immigration case showed improved and more transparent oversight was needed, he said.
One of the review's recommendations includes expanding the Intelligence and Security Committee's role beyond the GCSB and SIS to other agencies with significant intelligence collection and assessment functions that bear on national security, including Defence Intelligence, Customs Intelligence, Immigration Intelligence and Police Intelligence.
"The major change recommended in relation to the three oversight mechanisms discussed in this chapter concerns the Intelligence and Security Committee," wrote the authors.
"Without a restructured committee with greater independence from the executive, an increased mandate, enhanced powers and greater resources, New Zealand will lack effective democratic oversight of the agencies and the intelligence community more broadly.
"In our view, it is now time to rectify that deficiency in our oversight arrangements and go some way to catching up with what comparable countries are doing."