Players involved in a mixed doubles match at the Australian Open say they were interviewed by the Tennis Integrity Unit (TIU) after newspaper reports of suspicious betting patterns.
The New York Times said an online bookmaker suspended betting as Lukasz Kubot and Andrea Hlavackova beat David Marrero and Lara Arruabarrena 6-0 6-3.
Most of the money was placed on Spain’s Marrero and Arruabarrena to lose.
All four players rejected the possibility of match-fixing.
Spanish pair Marrero, 35, and Arruabarrena, 23, rejected the allegations in an interview with the Times, with Marrero blaming a knee injury for the pair’s poor display.
Pinnacle suspended betting before the match and notified local police.
However, Bookmakers William Hill, a sponsor of the Australian Open, say they saw no suspicious betting activity on the match, while Betfair said it also kept betting open.
Both Kubot, 33, from Poland, and his Czech Republic partner said they had never been approached by the TIU before, and both players said they were unaware of anything unusual or irregular about the match.
“It’s not very comfortable to think that we didn’t win the match on our terms,” said Hlavackova, 29. “We played our best, we did very well and we won.”
Governing body Tennis Australia declined to comment on the case, reiterating in a statement that the TIU’s policy is “to review and investigate every allegation of corruption in tennis”.
The sport has been under intense scrutiny in the wake of reports published by BBC and BuzzFeed News on 18 January saying authorities had ignored widespread evidence of match-fixing involving 16 players who had been ranked in the top 50 over the past decade.
In a separate unrelated case, former top-200 tennis player Nick Lindahl has pleaded guilty in a Sydney court to a match-fixing charge. It came after prosecutors said the Australian informed two people he would intentionally lose a match at a lower-tier tournament in 2013 so they could bet against him.