The three-hour long interview was a key part of the police investigation into allegations Mr Banks had failed to file an accurate electoral return after losing his bid to become the first Auckland supercity mayor in 2010.
It gives a fascinating insight into the urgency behind fundraising for the election and the way politicians approach people for large sums of cash.
The New Zealand Herald sought the interview from police in 2012 in the wake of a police investigation that found Mr Banks had filed a false return but was not liable for prosecution because it was outside the six-month time limit for charges to be laid.
A further private prosecution was taken against Mr Banks by Wellington man Graham McCready, claiming the politician had filed the false return knowingly. His conviction on the charge at the High Court was overturned at the Court of Appeal.
Police released a summary of its initial investigation and then affidavits gathered from witnesses, but resisted releasing the transcript of the interview with Mr Banks. It is the only detailed account Mr Banks has given of his relationship with internet entrepreneur Kim Dotcom.
The interview shows Mr Banks to be clear about the number of visits made to Mr Dotcom's Coastesville mansion near Auckland.
In the interview Mr Banks said: "Well I asked him for money. Yes. And I think I asked him for money at that second lunch. That's the lunch we had after the helicopter (visit)."
Dealings with Dotcom
The case against Mr Banks collapsed after the events relayed by Mr Dotcom and supporting witnesses failed to find a way to exist in an agreed timeline.
Mr Dotcom has since said the timeline is not accurate and described a previously forgotten encounter between him and Banks at which discussion about donations was made. In total, it would have been four mansion visits.
Mr Banks' original interview records his belief that he had visited on three occasions - an original helicopter visit, a lunch visit with wife Amanda and a visit for Mr Dotcom's birthday.
He told detectives of how he and Mr Dotcom had sat in a conservatory outside and talked about the campaign and fundraising.
He told Mr Dotcom he wanted donations of $25,000 but rejected suggestions from the then-tycoon that he be given $200,000.
Mr Banks appeared lost when it came to the technology help Mr Dotcom was able to offer. Mr Dotcom told Mr Banks he could help him with "social media" - and the politician later told police: "I thought it could be something to do with the girls he had at the birthday party but it wasn't that."
Instead, it was Twitter "and all the other stuff" which meant "I could communicate with everyone in Auckland".
"I thought a Megaupload was something my cat did when it ate too much."
Police balked at providing the interview even after being ordered to by the Ombudsman in December 2013, saying it could interfere with the upcoming private prosecution action. The interview with police was aired in court, but Justice Edwin Wylie refused to allow access to the court file for a copy of the transcript.
The Court of Appeal then threw out the conviction against Mr Banks' case, which also appeared to clear the way for releasing the transcript. Police - which had no role in the case at that stage - said it intended waiting 20 more days in case there was an appeal against the court's decision.
Police concern at transcript's release
Police had originally expressed concern over the release of John Banks' interview transcript on the grounds it would have a chilling effect on others who might otherwise have provided information to authorities.
The New Zealand Herald argued that Mr Banks had repeatedly said he had "nothing to fear and nothing to hide", and promised "everything will come out in the wash" while invoking his office as Justice of the Peace.
The Herald told the Ombudsman that Mr Banks had used the assurances as a shield in calling for patience and releasing the police interview was part of the "wash" to which the politician had referred.
It was also argued that the three-hour police interview was the only time Mr Banks had detailed the events leading up to receiving donations from Mr Dotcom.
Professor Rob Paterson said those standing for or in public office could expect to lose a degree of privacy. He said an MP with legal representation interviewed about "alleged irregularities in respect of electoral funding donations" could not expect a "high expectation of privacy".
"Given the public disquiet about the integrity of the fundraising for the 2010 Auckland Mayoral election, without direct access to Mr Banks' statement, the public will not be adequately informed."
The Ombudsman said Mr Banks had opposed the release with his lawyer, arguing it would encourage "irresponsible commentary".
The Ombudsman said it was not a valid reason for refusing to supply the information when the test to be applied was whether it was in the "public interest".
