The father of American tennis sensation Melanie Oudin is reportedly seeking a divorce from her mother, alleging Leslie Oudin had an affair with the teenager's coach.

Sports Illustrated's Web site reported that Oudin's father, John, filed for divorce in July 2008 on grounds of adultery.

According to the report, John Oudin said in a sworn statement last month that his wife had an affair with the 17-year-old's coach, Brian de Villiers.

Melanie Oudin's parents were married in 1989 and have three daughters.

John Oudin was not in his daughter's guest box Wednesday night for her U.S. Open quarterfinal loss to No. 9-seeded Caroline Wozniacki of Denmark.

According to SI.com, John and Leslie Oudin agreed to several conditions in a temporary order dated Dec. 16, 2008, including a stipulation "that (Leslie) will not interact with Brian de Villiers except as it specifically relates to the children's tennis activities ... (and) not to travel with Brian de Villiers to any tennis tournaments in which the children are participating."

The Oudin divorce proceedings are ongoing, the Web site reported.