After six years of furious speculation and rampant misidentification, the real Belle de Jour has finally stepped forward into the limelight.
And she is?
A research scientist with a PhD in forensic science.
Dr Brooke Magnanti, a blonde 34 year old, said on Sunday that she had decided to identify herself because of a "perfect storm" of feelings and circumstances about her secret life.
The lightening rod in that storm appears to have been an ex-boyfriend who was threatening to go public.
Dr Magnanti, whose ability to cloak her identity has amazed the literary world, decided to end on her terms a guessing game that started with her blogging about her decision to turn to prostitution for some extra cash.
The blog, Diary of a London Call Girl, which took a humorous approach to getting paid for sex while failing to condemn it, quickly gained a loyal following.
It was picked up by a publisher, turned into a best-selling book and transformed into an ITV2 television series, Secret Diary of a Call Girl, starring Billie Piper.
Dr Magnanti, whose PhD is in epidemiology, informatics and forensic science, on Sunday told her followers: "A perfect storm of feelings and circumstances drew me out of hiding. And do you know what? It feels so much better on this side."
She continued: "Anonymity had a purpose then – it will always have a reason to exist, for writers whose work is too damaging or too controversial to put their names on.
"But for me, it became important to acknowledge that aspect of my life and my personality to the world at large."
Being anonymous, she said, was "no fun" because she could not even attend her own book launches.
Dr Magnanti decided to try working for a high-end escort agency because she was running out of money while completing her thesis at Sheffield University in 2003, she said.
When it got to the stage that she could not afford her rent, she asked herself: "What can I do that I can start doing straightaway, that doesn’t require a great deal of training or investment to get started, that’s cash in hand and that leaves me spare time to do my work in?"
The answer came in the form of charging £300 an hour as a prostitute, that she did for the next 14 months.
As Belle de Jour's profile grew, so the hunt to 'out' her intensified.
She could not reveal her identity to anyone – parents, friends, or even her literary agent, she said.
Speculation as to the author's identity never got close, with names in the frame ranging from The Daily Telegraph's Rowan Pelling, former editor of the Erotic Review, to Toby Young, the author.
Pelling, in fact, was one of the few people to have an idea of the truth, having met Dr Magnanti in an anonymous interview arranged by a book publisher.
"it's pretty amazing she has managed to keep it a secret," she noted.
Dr Magnanti is now a specialist in developmental neurotoxicology and cancer epidemiology at the Bristol Initiative for Research of Child Health. When she told her colleagues about her secret life about a month ago she said they were "amazingly kind and supportive".
She was planning to tell her parents over the weekend.
Despite Belle de Jour's positive reception in literary circles, she has been criticised for glamorising prostitution.
The Rev John Sentamu, the Archbishop of York, last month said there was "little mention of how destructive sex for cash can be" in attitudes epitomised by Belle de Jour.
It was left to Piper to defend the-then faceless Belle. The actress said: "We've only been exposed to the drug-fuelled, sex traffic side – but the fact is, there are middle-class, cultured, well-read women who take part in this job."
