Wozniacki, a 19-year-old Dane ranked sixth in the world, retired from the first-round match at the Luxembourg Open with a hamstring injury on Wednesday while leading Anne Kremer of Luxembourg 7-5, 5-0.
Wozniacki's father, Piotr, told his daughter at 3-0 in the second set to retire before winning because her injury would prevent her from playing in the next round. His comments, apparently spoken in his native Polish, were picked up by microphones and heard by viewers watching the match on the Internet.
"I went onto the court and said to her: 'Caro, it does not matter whether it's going to be 5-0, 4-1 or 3-2. You can not play the next round, so you shouldn't take the risk,'" Piotr Wozniacki said Thursday on Danish radio. "I'm very proud of Caroline, because she stopped the fight and gave her opponent a chance."
The father's comments during the match led to a surge in online bets for Kremer to win.
The governing bodies of tennis created a Tennis Integrity Unit last year to combat gambling and match-fixing.
"We're just looking into everything that happened in this match," WTA spokesman Neil Robinson said, adding that he believed the information would go to the integrity unit. "I would think that would be the way it would go. They are aware of it."
The Tennis Integrity Unit does not comment on cases, and neither would Betfair, an online gambling site that works closely with tennis authorities.
"Under the terms of our memorandum of understanding with sporting bodies worldwide, it is up to the sporting authorities to comment," Betfair spokesman Tony Calvin said. "However, it is reasonable to assume that in high-profile cases like this, correspondence has been made."
Betfair, however, said it did not have any concerns about the match at this stage, and that the money won or lost was not unusual.
In Danish newspaper Ekstra Bladet, Wozniacki professed her innocence.
