The employers of a research scientist who unmasked herself as a call girl turned bestselling author are standing by her, saying that her past had nothing to do with her present job.

After much digging by journalists and fans it emerged that Belle de Jour is Brooke Magnanti, a petite, blonde thirtysomething who works as a specialist in developmental neurotoxicology and cancer epidemiology in a hospital research group in Bristol.

A month ago she revealed her secret to her colleagues at the Bristol Initiative for Research of Child Health, who were “amazingly kind and supportive”.

Dr Magnanti, who is based at St Michael’s Hospital in Bristol and employed by the University of Bristol, unmasked herself as the literary world’s best-kept secret after admitting in her online blog that she felt “worse” about her writing than about her life as a high-class prostitute.

Barry Taylor, a university spokesman, said: “This aspect of her past bears no relevance to her current role at the university.”

Dr Magnanti was a PhD student working on her thesis at Sheffield University when she decided that prostitution would be a quick, easy and relatively painless way to earn some cash.

For 14 months from October 2003 she recorded her sexual encounters in her online blog with a frankness, humour and style that won her many admirers and led to a six-figure book deal.

It inspired the ITV2 drama, The Secret Diary of a Call Girl, starring Billie Piper, the former pop star and Doctor Who actress. Dr Magnanti said it was a relief to emerge from the shadows of anonymity that had meant that she could not even go to her own book launch.

She wrote: “It feels so much better on this side. Not to have to tell lies, hide things from the people I care about. To be able to defend what my experience of sex work is like to all the sceptics and doubters.”

She said she took advantage of the opportunity presented by a “perfect storm of feelings and circumstances”.

She is believed to have decided to out herself after reporters from a national newspaper turned up at the hospital in Bristol where she now works. Realising that the game was up she approached The Sunday Times and gave an interview to India Knight, who had previously disparaged her book and suggested that it was a work of fiction written by a man.

Now 34 and researching the impact on child health of exposure to environmental toxins in the womb, Dr Magnanti had never even been a suspect in the search for “Belle”. Instead the literary world questioned whether Belle was a “real” person and turned to more famous suspects, including the novelist Sarah Champion and the journalist Toby Young.

Dr Magnanti bears a far closer resemblance to the French actress Catherine Deneuve, who starred in the 1967 film from which she borrowed her pen name. The original Belle de Jour was a frustrated housewife who worked in a brothel between 2pm and 5pm every afternoon.

Yesterday there was no sign of her at St Michael’s Hospital. She moved to Bristol eight months ago, four years after giving up her night job.

Dr Magnanti had more to say in her blog. She wrote: “I suppose I always thought that the part of my life I wrote about would fade away, that I could stick it in a box and move on. Totally separate it from the ‘real me’.

“What it took me years to realise is that while I’ve changed a lot since writing these diaries my life has moved on so much, in part thanks to the things that happened then. Belle will always be a part of me. She doesn’t belong in a little box, but as a fully acknowledged side of a real person.

“The non-Belle part of my life isn’t the only ‘real’ bit, it’s all real.

“Belle and the person who wrote her had been apart too long. I had to bring them back together.” She signed off: “I am a woman. I lived in London. I was a call girl.”

Dr Magnanti said in her interview that while she had no regrets about her past she would not consider returning to prostitution. She is in a serious relationship with a man who knew about her past before they became involved.

One person who did not know the identity of Belle was her agent. Another was her mother. She told The Sunday Times that she would be breaking the news to her before her mother saw the story on the front page of the newspaper.

Anonymous authors unmasked

Joe Klein, a journalist, was unmasked as the author of Primary Colors, a thinly disguised exposé of the darker side of Bill Clinton’s first White House election campaign. In July 1996, five months after publication and having issued lengthy denials to Newsweek and The Washington Post, he owned up

Richard Bachman sold 28,000 copies of his first novel, Thinner. But when it was suspected that the author was Stephen King, sales soared. King denied writing as Bachman and the latter’s books even carried an “author photograph” that, in reality, depicted a friend of King’s agent. A bookstore owner eventually outed King who, before being exposed, had planned to write his hit novel Misery in the guise of Bachman. King admitted that he chose to write anonymously to see if his success was down to skill or good fortune

Daniel Lyons, a senior editor at Forbes magazine, anonymously ran a website on which he pretended to be the CEO of Apple, a character that he called Fake Steve. His blog, The Secret Diary of Steve Jobs, amassed a huge following among Silicon Valley’s elite. Lyons kept his secret for 14 months, but was uncovered when attempting to sell the idea to book publishers

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