Oprah Winfrey's all-girls boarding school in South Africa has been hit by a second sex scandal since opening two years ago.

Seven students at the Oprah Winfrey Leadership Academy School for Girls near Johannesburg were suspended last week for sexually harassing their schoolmates, according to the Afrikaans on Sunday newspaper.

One 15-year-old "preyed" another student and urged her victims to lie to investigators about what happened, the paper reports.

See photos of Oprah and other stars who have survived abuse

Other girls were alleged to have been "intimidating others into partaking of inappropriate behaviors" at the $46 million school, according to the report.

A letter sent to one of the suspended girls' parents reportedly read: "You have been found guilty of physical contact of a sexual nature with another pupil on campus, harassment, bullying other girls on campus and of being dishonest by not telling investigators the whole truth."

Look back at Oprah's weight highs and lows

Lisa Halliday, a rep for Winfrey, declined to comment on specifics but confirmed the girls had been suspended: "It is because they contravened the school's code of conduct. We regard the incident as confidential."

Winfrey opened the school in 2007, calling it the proudest day of her life.

See today's top celeb news photos

About 10 months later, 15 girls reported they had been sexually abused by a matron, Virginia Tiny Makgobo, 27. (The matron denies the charges and is due back in court on June 1.)

Fighting back tears, Winfrey said at the time, "This has been one of the most devastating experiences, if not the most devastating experience, of my life. But like all such experiences there is much to be learned."