Asked if there was any reason why they would make such serious allegations, Cairns said he been "wracking his brains" for months but didn't want to come across as a "whack job" who believed in conspiracy theories.
Excerpts of the recorded interview between Detective Constable Lucy Wade, the officer in charge of the Metropolitan Police investigation, and Cairns were played to the jury at the Southwark Crown Court overnight.
Cairns started the interview by saying he had a "soft spot" for Lou Vincent when he played for New Zealand and looked out for him when he played at the Chandigarh Lions in the Indian Cricket League.
He told the detective that Vincent was erratic, had his "ups and downs" with mental health - including suicide concerns - and dabbled in drugs while playing in the ICL.
These concerns about Vincent with raised in a conversation Cairns had with Tony Greig, the television commentator and chairman of the unsanctioned Twenty20 league.
Cairns explained that he did ask Vincent for a statement to support him in the defamation case against Lalit Modi, the powerful cricket official who tweeted that Cairns was involved in match-fixing.
He said Vincent told him he was going through "tough times" and Cairns thought he was asking for remuneration in return for his support.
"He never said money, I never said money. But without a shadow of a doubt, we were talking about money."
Cairns did not offer any, but there was a wider discussion about a coaching job for Vincent in a potential cricket television show Cairns was involved with.
In a second excerpt of the interview, Ms Wade asked Cairns about a dinner and night of drinking at the Manhattan Bar in Grill in Hale in 2008.
Lou Vincent said it was a "celebration" of a match he played for Lancashire in which he successfully underperformed on the alleged instructions of Chris Cairns.
His wife at the time, Eleanor Riley, said she raised concerns that night about match-fixing with Cairns and alleged he reassured her they would not be caught.
Cairns told Ms Wade that it was not a celebration but an evening where they had a "few more beers" because "f***ing Fred Flintoff turned up".
Asked why the Vincents would make such allegations, Cairns said he had been "wracking his brains" for months and did not want to seem like a "whack job".
He had been "f***ed over" by the allegations leaked in the media and could not make a living to pay the bills and look after his family.
Cairns could not understand why someone did not speak to him earlier about these allegations and did not offer a reason for why the Vincents made the match-fixing allegations.
"I don't want to go into conspiracy theories...I'm getting f***ed over."
The third extract played to the jury was when Cairns was asked about his relationship with Brendon McCullum.
Cairns described "Baz" as a younger player who was "in my sort of mould, aggressive" and they had a natural rapport.
"I enjoy a beer with Baz and an occasional fag, if you like, in a bar."
He was asked about a meeting in his hotel room in Kolkata in 2008 where McCullum alleged Cairns approached him about match-fixing.
Cairns said there may have been a general discussion about spread betting and rumours of who might be involved, or how much they were paid.
But he categorically denied making a corrupt approach and McCullum had "misconstrued" the conversation.
"I told Brendon McCullum not to miss out on spread betting? No," said Cairns.
"A direct scenario in which [McCullum] can benefit? Absolutely not."
Cairns has pleaded not guilty to charges of perverting the course of justice and perjury, while his friend Andrew Fitch-Holland has pleaded not guilty to perverting the course of justice.
The Crown is expected to conclude its witnesses tonight [NZT].
- By Jared Savage in London
