A senior Labour politician was spied on by the SIS while an MP in the 1980s and 1990s - even though for part of that time he had an oversight role of the intelligence agency as chair of the justice select committee.
Richard Northey, a Labour MP between 1984 and 1990 and again between 1993 and 1996, said it was "outrageous" that the SIS had kept a file on him while he was a sitting MP with a democratic mandate.
The revelation from Northey comes in an interview for The Service, a new RNZ podcast series investigating the activities of the SIS during the Cold War.
Northey, who challenged for the Labour leadership in 1990 but lost to Mike Moore, said he requested his SIS file in 2014 and found it had been active all the years he had been an MP.
"I think it's outrageous. I don't think that somebody who gets sufficient democratic support to become a member of Parliament should be subject to surveillance by the intelligence agency."
After a request from RNZ, the SIS declassified documents held by Archives New Zealand, including letters sent and received by Northey while he was chair of the justice select committee overseeing the SIS Amendment Bill in 1989.
The documents included correspondence between Northey and then-prime minister David Lange, then-deputy prime minister Geoffrey Palmer and also advice Northey received from the commissioner of security warrants.
The documents, and Northey's interview, revealed that while he was chairing the committee scrutinising changes to legislation determining how the SIS obtained interception warrants and who oversaw that process, he was being surveilled by the intelligence agency itself.
Northey, who was awarded the Order of New Zealand in 2001 and now chairs the Waitematā local board in Auckland, campaigned strongly against nuclear weapons and racism in the 1980s.
Northey said he anticipated his anti-nuclear campaigning would attract SIS attention as it had implications for the Five Eyes alliance.
He did not expect his advocacy for racial equality would draw the agency's attention.
"I don't believe that being more assertive about racial equality in New Zealand and overseas is a threat to New Zealand security. So I was concerned when I got the report that that had been a matter of interest to the SIS," he said.
"I'm pretty sure my phone wasn't tapped or anything like that. There's absolutely no record of anything coming from that source. It's just notes taken at meetings and conversations."
The Northey file was one of a number of issues RNZ sought to discuss with SIS director Rebecca Kitteridge but she declined an interview.
The issue of SIS keeping files on MPs blew up in 2009 when Green MP Keith Locke discovered the intelligence agency had been spying on him since he was 11.
In 2018, the agency apologised to him for calling him a "threat" in internal documents - speaking notes for an induction programme run by the SIS and the GCSB since 2013.
When Locke's SIS file first became public, then-prime minister John Key commissioned a report by the Inspector General of Intelligence and Security, Justice Paul Neazor, who laid out new rules for the SIS when gathering intelligence on MPs.
The 2009 Neazor report said "it would be reasonable in New Zealand to regard a sitting MP, because of his or her function and standing, as not generally a proper subject for intelligence collection or surveillance".
The report did not rule out SIS surveillance on MPs but said the agency should show Parliament's speaker it had good grounds to believe an MP's activity was "prejudicial to security".
Under an agreement with the SIS and the speaker an existing file is to be deactivated if a person becomes an MP and not added to while they are in Parliament, except if they are considered a security risk.
Under the Intelligence and Security Act 2017, the SIS is supposed to be a politically neutral agency, which forbids it from harming or promoting the interests of any party or candidate.
The Service was made with the support of New Zealand on Air