The husband of Swiss tennis player Martina Hingis is alleging that she cheated on him and that she is a "serial adulterer."

Days after separating, Hingis' husband Thibault Hutin told Swiss newspaper Schweizer Illustrierte that he tried to salvage the marriage last year but stumbled upon her with another man in a hotel room.

"Upon arriving at the hotel room it was me that was surprised, because Martina was not alone," Hutin said. "Late last year I found out that she had cheated on me again."

The 26-year-old equestrian noted that Hingis had cheated on him at least twice before separating on Monday, adding, "I think she has always been unfaithful to her boyfriends."

Hutin explained that Hingis was not alone in the tennis world in terms of her cheating but said that he thought she was different and that she truly loved him. He said that there were even pictures that Hingis and her new lover took that surfaced, adding that he was crushed by them.

The new lover in question is a man named David Tosas Ros, a Spanish sports management executive.

Hingis, 32, has not responded to any of Hutin's accusations.

Once one of the biggest names in tennis, Hingis won three consecutive Australian Opens between 1997 and 1999 in addition to one U.S. Open and one Wimbledon championship. She was also No. 1 in doubles matches for 35 weeks, making her one of five women in the history of tennis to be No. 1 in singles and doubles simultaneously.

Hingis retired from the sport in 2002 due to an injury but came back in 2006. She then tested positive for cocaine in her system and quit in 2007 despite denying the International Tennis Federation banning her from the sport.

Watch this interview with Hingis at Wimbledon in 2012: