The US celebrity told students they can contact her directly

Police from Gauteng's child protection unit are investigating allegations of sexual and physical abuse by a matron.

Ms Winfrey has visited the school at Henley-on-Klip near Vereeniging at least twice in the past few weeks.

The school has suspended the principal and two matrons and has offered counselling to its 150 boarders.

One girl at the school complained she had been fondled while others reported being sworn at, grabbed by the neck, beaten or thrown against a wall.

The girls said they had told the principal, Dr Mzimane, but she had failed to act.

Tearful disappointment

South Africa's news24 website says that a visibly upset Ms Winfrey told parents she had trusted the principal, Dr Mzimane and felt let down, "I've disappointed you. I'm so sorry. I'm so sorry."

Parents also told Rapport newspaper that Oprah had given the girls her personal telephone number, e-mail address and postal address saying they could contact her directly at any time.

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A father of one of the pupils told her at the meeting: "It's not your fault. We don't blame you.... You have more passion for the school... than anyone else in this country."

News of the alleged abuses first broke on 17 October when the school announced the suspension of one "dorm parent" and said it had notified child protection services of allegations of misconduct.

School CEO John Samuel told Rapport newspaper that the school had "engaged professional investigators of the highest standing from South Africa and the United States to conduct a fair and impartial inquiry into the claims."

The team, which includes a retired Chicago policeman, handed over a dossier of statements from schoolgirls to the head of Gauteng's child protection unit, Superintendent Andre Neethling.