Trial to lift veil of secrecy over Oprah's African academy

Talk-show host's dream of helping poor children rocked by abuse allegations at girls' school near Johannesburg

As a talk-show queen with a $2bn fortune, a role model and mega-celebrity, Oprah Winfrey is comfortable with the limelight – except, it seems, when it comes to the school for poor girls she founded in South Africa. Her visits are shrouded in secrecy, and guests at a recent function had to sign an agreement banning cameras and camera phones.

But this week, life inside the Leadership Academy for Girls near Johannesburg, into which she has poured more than $40m (£20m), will be closely examined in court. On Tuesday, Virgina "Tiny" Makgabo, 27, a former matron at the school, faces charges of indecently assaulting minors, verbally abusing them and soliciting them to perform indecent acts. Court sources do not expect Winfrey to attend the three-day trial.

Reports alleged the matron or "dormitory parent" grabbed a girl by the throat and threw her against a wall. Ms Makgabo was accused of swearing and shouting at girls and fondling at least one pupil. The allegations surfaced last October, when a student ran away from the school, claiming the situation had become intolerable.

The accusations have proved an embarrassment for Winfrey, who has since made regular discreet visits to the school to reassure parents. Information has been closely controlled: no telephone numbers appear on the school's website. Winfrey has said little about the affair, and parents have been warned against speaking to the media.

The case is an unhappy contrast to the high-profile opening of the academy in January 2007, when Winfrey received congratulatory messages from Nelson Mandela, among others. He was credited with getting her involved in education in South Africa, after she staged a series of Christmas shows for poor children three years before.

The result was a campus on 52 acres in Henley-on-Klip, south of Johannesburg. Girls whose parents earn less than £350 a month can apply for places. The benefactor claimed it would be a "model school for the rest of the world".

But the philanthropy has come at a price. When the abuse accusations first surfaced, Winfrey said: "Nothing is more serious ... than an allegation of misconduct by an adult against any girl at the academy. I will do everything ... to ensure their safety." On a school visit two weeks later, she told parents: "I've disappointed you. I'm so sorry"

Winfrey herself suffered abuse as a child by a cousin, uncle and family friend – experiences she has shared with her TV audiences.

She says she does not regret opening the academy, telling a music station: "From the very first half hour, after I was able to pull myself together, I knew that this too shall pass. And the girls are now fine. The school is going to be better because that happened."