Although Masters tournaments aren't as prestigious as the four grand slams, their draws are usually considerably smaller than the singles field of 128 at majors and thus feature higher-ranked players.
The BBC said the South American played on the tennis tour last year but is now a coach. The player had requested anonymity before talking to the BBC.
The fresh report and a BBC radio program that aired Tuesday in the UK came in the wake of the original one Monday which said grand slam winners in both singles and doubles
were among those reported to authorities for losing games when "suspicious" bets were placed against them.
No names were mentioned and several players who have spoken to CNN said the investigation lacked proof and was dated. In the BBC's follow-up radio program there was no mention of a grand slam singles champion being reported.
Austrian journeyman Daniel Koellerer told the BBC he was offered money to throw matches in 2009 at the French Open and in Chennai and Moscow. He said he refused the offer.
Koellerer, who earned the nickname "Crazy Dani" for his controversial on-court antics, became the first player banned for life for match fixing in 2011.
"I think that the story that was written was rubbish because they're just pouring dirt on our sport without proving anything," Sergiy Stakhovsky, a longtime member of the ATP's player council, told CNN.
"And what we need is facts, facts, pure facts. Names, statements, settlements. Payments, pictures, something."
The outspoken Ukrainian chatted while glancing at scores on television screens near the men's locker room at the Australian Open and revealed how a misleading scoreline could mistakenly be construed as suspicious behavior by a player.
He referred to a second-round match between David Goffin -- who beat Stakhovsky in the opening round -- and Damir Dzumhur on Tuesday.
Goffin, the considerable favorite ranked 16th, won the first set but then lost the second 6-0 to the world No. 81.
"Today I think Goffin was not far off losing to Dzumhur," said Stakhovsky. "Was he tanking? No. It's a sport where a lot of different parts must fit in for you to win a match."
Goffin ended up winning the match in four sets.
'They do their jobs like the FBI'
Stakhovsky also backed up the Tennis Integrity Unit (TIU), which was formed in 2008 after a match between former No. 3 Nikolay Davydenko and Argentina's Martin Vassallo Arguello in Sopot, Poland a year earlier. The ATP carried out an investigation following suspicious betting patterns but neither player faced sanctions.
The TIU and tennis authorities were accused this week of failing to thoroughly investigate match fixing claims. Lack of transparency has also been used as a criticism, most notably by twice grand slam champion Andy Murray on Tuesday.
But Stakhovsky wasn't buying that.
"They do their jobs like the FBI," he said. "Do they hold a press conference every year and say to the US people that we are investigating this and this? No they do not.
"They do their job and that's what needs to be done. They do their job and to the best of their knowledge. And that's what we have faith in, and we believe that through the years that we played they did the best they could because we paid them to do the best they could."
The ATP said it wouldn't be commenting on the matter Wednesday; the head of the ATP Chris Kermode denied on both Monday and Tuesday that any evidence was suppressed. He also reiterated tennis' zero-tolerance stance on match fixing.
Nigel Willerton, director of integrity at the TIU, said it was difficult to get evidence in cases because bank records, phone records and emails, for example, don't have to be submitted by those being investigated.
The TIU released a statement Wednesday urging the player "behind the allegations to make contact with the TIU and to share the information he claims to have."
Corrado Barazzutti, Italy's Fed Cup captain, said preventing match fixing is key.
"We have to do something maybe to stop it before it happens," he told CNN. "Maybe you have to do something if you know people (are) talking to people that (are) proposing something.
"I think (match fixing) is impossible to prove. If you don't catch the people while they're getting the money ... but then we can even discuss this, 'Why are they getting the money?' It's difficult. The system is not perfect but it's difficult to do something to stop that if match fixing is taking place."