Suspicions of match-fixing clouded the Australian Open on Monday after an online bookmaker reported an unexpected spike in bets on a mixed doubles match, a news report said.
Wagers poured in hours before an otherwise obscure match pitting a Spanish and a Polish pair, prompting website Pinnacle Sports to alert authorities in Melbourne where the match was held, the New York Times reported.
Lara Arruabarrena and David Marrero went down against Andrea Hlavackova and Lukasz Kubot 6-0, 6-3 on Sunday, with the first set lasting just 20 minutes, the report said.
Marrero blamed a knee injury for the result.
The integrity of the sport was under scrutiny after news reports last week said that more than a dozen top-50 players in recent years had been suspected of match-fixing, but that the allegations were not followed up by tennis officials.
After Sunday's allegations, tennis officials pointed out that unusual betting patterns can also be triggered by the leak of inside information, including for example of an injury that could influence a match, the New York Times report said.
"We saw a small number of people placing a large amount of money," said Marco Blume, head of sports betting at Pinnacle Sports.
"In context, these matches are rather small. That means that any aggressive betting behavior is very easy to detect on our side," he was quoted as saying.
Tennis Australia issued a statement saying it "will continue to work closely with the relevant police authorities and the Tennis Integrity Unit" but would not comment on any ongoing investigation.
The TIU was established in 2008 to look into allegations of corruption in tennis worldwide.
In a separate case, a former Australian tennis professional told a court Monday he would plead guilty to throwing a match in 2013.
Nick Lukas Lindahl, 27, is accused of deliberately losing a match in the Toowoomba Futures Six tournament to allow friends and contacts to win thousands of dollars, the Sydney Morning Herald reported. He has been on bail since February.