The judge in Chris Cairns' perjury trial has warned the jury to be careful in considering evidence from self-confessed cricket cheat Lou Vincent.
Cairns, a former Black Cap, has been on trial in London for the past seven weeks for lying under oath about match fixing during his successful libel case in 2012.
In that trial he said: "I have never, ever cheated at cricket. Nor would I ever contemplate such a thing."
Three witnesses are central to the crown's case - Vincent and Black Cap captain Brendon McCullum, who say Cairns approached them in 2008 to fix, and Vincent's estranged wife Eleanor Riley.
In his summing up, Justice Nigel Sweeney told the jury of seven women and five men that they must be sure two out of the three witnesses were telling the truth to convict Cairns of perjury.
He told the jury to be "particularly cautious" in assessing Vincent's evidence because "he might have his own interests to serve."
The jurors were reminded of Vincent's tarnished past; match fixing, failed attempts to recruit four other cricketers to fix, lies to cricketing authorities and an admission, while in the witness box, to offences of corruption, fraud, money laundering and bribery.
Vincent was never granted immunity in exchange for giving evidence against Cairns and was cautioned by the judge, who said he didn't have to answer any questions where he may incriminate himself.
However, it was now clear from a series of police emails and the evidence of a senior detective that "in reality Lou Vincent was not at risk of any crimes," the judge said.
Had the court known that, the caution would have been administered differently the judge said.
"Although not his fault, any impression his credibility was boosted was clearly wrong and shouldn't form part of your deliberations."
The judge told the jury Cairns was of good character, had no previous convictions and had been involved in charity work. While "good character isn't a defence as such... it supports his credibility and should [be taken] into account."
As well as perjury, Cairns also faces a second charge of perverting the course of justice along with his co-defendant, English barrister Andrew Fitch-Holland.
The pair have been accused of seeking a false statement from Lou Vincent to support Cairns' libel case.
Justice Sweeney told the jury they must consider the perjury charge first and if they found Cairns guilty then they could rely on it in considering the second count. However, he said if they found Cairns not guilty of perjury, then he also must be found not guilty of perverting the course of justice.
The "critical issue" in determining the perjury verdict was whether the prosecution had convinced the jury Cairns was a cheat, Justice Sweeney said.
Justice Sweeney will continue summing up on Monday. The jury is expected to retire on Tuesday morning.