A South American tennis player has told the BBC that match-fixing is commonplace and even some elite players are "a little bit dirty in some way".
He also claimed fixing is not just limited to lower-ranked professionals and is "a secret that everybody knows".
The player, who requested anonymity, said tennis authorities "know who is doing it" but are unwilling to stop it.
The Tennis Integrity Unit (TIU) said it rejects "any suggestion that evidence of match-fixing has been suppressed", BBC reports.
"We invite the player behind the allegations to make contact with the TIU and to share the information he claims to have," the TIU added in a statement.
The allegations come after a BBC and BuzzFeed News investigation revealed suspected illegal betting in tennis over the past decade.