The big news this morning is that the SIS have finally released their files on William Ball Sutch, the former public servant they unsuccessfully prosecuted for espionage in the 70's. The farcical nature of the prosecution led to major changes in New Zealand - notably a review of the SIS by then-Ombudsman Sir Guy Powles (the secret annex [PDF] of which contains some biting comments on the SIS's illegal activities) and subsequently a review [PDF] of the Official Secrets Act, a process which eventually led to its repeal and replacement by the Official Information Act.
As for the files themselves, the main one - a "target assessment" [PDF], summarising Sutch's background and all the information the SIS had on him, is pretty much what you'd expect: a web of paranoid supposition and character assassination displaying a conspiratorial mindset. In one section they assume for the sake of argument that he is a Soviet spy; later that assumption is somehow transformed into fact. The overall conclusion? "[D]uring his 66 years we have accumulated six files on Sutch, and yet can prove nothing of which he is suspected". And yet, they regarded him as guilty. Which rather speaks for itself about the SIS's regard for evidence.
There's an obvious parallel here with the Zaoui case - the same paranoia and self-reinforcing web of suspicion despite all the evidence. While the Sutch case led to major changes in New Zealand, clearly nothing has changed in our spy agency.