In an unprecedented move, the head of New Zealand's top spy agency is expected to apologise to former Labour leader Phil Goff this morning.
Inspector General of Intelligence and Security Cheryl Gwyn launched an inquiry in the middle of the election campaign following revelations in Nicky Hager's book Dirty Politics that Whale Oil blogger Cameron Slater was given information from the Prime Minister's office about what to ask for in an Official Information Act request in 2011.
The request related to accusations from John Key and National that Mr Goff had lied about a briefing about alleged Israeli spying in Christchurch.
At the time, Mr Goff said he hadn't received a top secret briefing from then spy agency head, Warren Tucker.
The Government attacked Mr Goff's credibility after Dr Tucker insisted he had briefed him.
ONE News understands Ms Gwyn's report will be released this morning and will heavily criticise Dr Tucker.
Rebecca Kitteridge, Director of the New Zealand Security Intelligence Service, is expected to personally apologise to Mr Goff at Parliament over the agency's handling of the case.
The report is understood to say Dr Tucker "lacked professionalism" in his dealings with Mr Key and his staff over the issue, leading to a "politically partisan affect".
It says his relationship with Mr Goff was "unfair" and "unprofessional" and his engagement with the Prime Minister's office was "not appropriate".
While it is critical of Mr Key's office, the report does not directly criticise him personally.
In the report, it's understood Ms Gwyn says Dr Tucker and his staff gave "incomplete and inaccurate information to the Prime Minister" which was unfair to the then leader of the opposition.
The report also confirms former National Party staffer Jason Ede told Mr Slater to ask for information about Mr Goff's briefing under the Official Information Act.
It's understood Ms Gwyn has used phone records to verify that while Mr Ede was on the phone to Mr Slater about the issue, the blogger lodged the Official Information Act request relating to whether Mr Goff had been briefed.
Mr Key denied during the election campaign that his office had anything to do with the fast tracking of the OIA request.