A French magistrate is investigating allegations by the retired Dutch supermodel Karen Mulder that she was raped by a member of a European royal family, other famous people and leading figures in the French modelling industry.

Ms Mulder, 33, first made the allegations during the recording of a French television programme before a studio audience last month. Her claims were regarded as so devastating, and so potentially libellous, that the interview was cut from the show.

However, Ms Mulder had made almost exactly the same accusations in a statement to French police several days earlier. The public prosecutor's office in Paris confirmed yesterday that it was taking her allegations seriously enough to start a criminal investigation for "rape by persons unknown".

Her allegations will be investigated by an examining magistrate, Jean-Pierre Gaury. Sources in the public prosecutor's office said he would be looking at physical and other evidence which appeared to corroborate at least part of Ms Mulder's story.

Ms Mulder, born in the Netherlands in 1968, was for many years among the 10 best-paid models in the world. She retired a year ago and is currently being treated in a private psychiatric clinic in Paris.

The former supermodel was invited to record an interview on 31 October for a show on France 2 television, called Tout le Monde en Parle (Everyone is Talking About It). The intention was to revisit allegations made by a BBC documentary two years ago that young models were often sexually exploited by leading figures in the modelling industry. To the astonishment of the show's presenters and the studio, Ms Mulder dissolved into tears and said she had been persistently raped from her childhood up until last April.

She alleged that she had been "hypnotised" and raped by modelling agency executives and a series of well-known men, including a member of a continental royal family.

The interview was cut from the show and the studio audience was sworn to secrecy. Nevertheless, accounts of what happened have been circulating on the internet and by e-mail for the past four weeks.

An e-mail account by a person claiming to have witnessed the television show says Ms Mulder claimed to have been raped by an "incalculable number of famous people in France and abroad".

Yesterday the newspaper Le Parisien reported that Ms Mulder had previously approached French police and made a formal statement containing very similar allegations to those made on the show. The public prosecutor's office confirmed yesterday that it had ordered an investigation against "X" (or persons unknown) for rape.

"Considering the celebrity of the complainant, but also taking account of evidence which she has provided which could form the basis of proofs, we have decided to appoint an examining magistrate to investigate the case," a judicial source told Le Parisien.

The source said the information to be examined included "physical evidence".

The newspaper said the judge would now be seeking a medical report on Ms Mulder, who was said to be in a state of "acute distress".

Friends of the model told Le Parisien that her psychiatric problems might be connected to her difficulties in adjusting to her retirement a year ago.

But Ms Mulder's friends also pointed out that the former supermodel had been known as a level-headed person, who had always been prepared to lend her celebrity to help charitable causes.