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.