Greig was the chairman of the Indian Cricket League, which is at the centre of the matchfixing allegations in the trial, but passed away in December 2012.
Brendon McCullum then gave a statement in February 2011 alleging Cairns had approached him twice in 2008 to fix matches, after Mr Rhodes gave a presentation to the New Zealand cricket team in Nagpur ahead of the cricket world cup.
Daniel Vettori, the captain of the New Zealand team at the team, was present at the interview as a support person.
Then in October 2012, Mr Rhodes interviewed Vincent who had played for the Auckland Aces at the Champions League tournament in South Africa.
There had been a complaint from Azhar Mahmood, also playing for the Aces, that Vincent had approached him to spot fix during the T20 tournament.
During that interview, Vincent told Mr Rhodes that someone had approached him to fix and gave the investigator their name and contact details. They turned to be false.
The following year, in August 2013, Mr Rhodes and a fellow ACSU official Martin Vertigen travelled to New Zealand to interview Vincent again following a tip-off from a confidential source.
He spoke to David White, the chief executive of New Zealand Cricket, as well as Heath Mills who is the president of the New Zealand Cricket Players Association.
But after speaking with Mr Mills, the ASCU investigators decided to wait to speak to Vincent.
"It was very obvious to us that [Mr Mills] had some information, which he did give....
Lou Vincent was not fit to be interviewed at that time."
Vincent had previously told the court that he had confessed to Mr Mills by this stage.
The following month, Mr Rhodes and Mr Vertigen interviewed Vincent for the first time at the offices of his Auckland barrister Chris Morris.
They continued to investigate his allegations during the end of 2013, interviewing Vincent several times as well as his former wife Ellie Riley and friend Steve Pearson, as well as re-interviewing McCullum in Bangladesh and Christchurch.
Then the Herald broke the news that the ICC was investigating Vincent, Cairns and their Chandigarh teammate Daryl Tuffey in December 2013.
Mr Rhodes then told the court how Chris Cairns called him in February 2014 to try and organize an interview.
Cairns told him he was "struggling", said Mr Rhodes, and the investigation was having a huge impact on his family.
Mr Rhodes replied that he understood but the ICC were not in a position to interview him yet, as the investigation was not finished.
Under cross examination by Orlando Pownall QC, Chris Cairns' defence lawyer, Mr Rhodes conceded he was wrong about the date and location of his 2011 interview with McCullum.
Mr Pownall asked Mr Rhodes why McCullum asked for his statement to not be given to New Zealand Cricket and whether that was normal.
Mr Rhodes replied that players sometimes feared "reprisal" and the ACSU would often honour a request to keep it private.
He confirmed that failing to report a fixing approach was a breach of the ICC code of conduct, punishable by a playing ban, but denied that he had ever had a discussion with McCullum about the possible repercussions.
Mr Pownall then criticized the ACSU for doing "nothing" after McCullum gave his statement in February 2011.
Mr Rhodes responded that the ICL was an unsanctioned tournament and the ICC had no powers to interview any of the players allegedly involved.
In response, Mr Pownall pointed out that Cairns - if he was a matchfixer as McCullum alleged - could have continued to matchfix around the world.
The QC said a very serious allegation was made by a senior player, supported by his New Zealand captain, against a "revered" international player in Cairns.
"This was potentially momentous?"
Mr Rhodes said he disagreed.
"The information at that time was not corroborated by any other source. I would need to corroborate it, for it to become momentous."
Mr Pownall shot back: "Absolutely nothing happened. Absolutely nothing."
Mr Rhodes explained that as a field officer, his job was to collect information and send it to ACSU headquarters in Dubai for further assessment.
Cross examination of Mr Rhodes will continue overnight before his colleague Mr Vertigen gives evidence.
