Pseudonym

Her pseudonym recalls the 1928 novel Belle de jour by Joseph Kessel and the 1967 film of the same name starring Catherine Deneuve, directed by Luis Buñuel. In French "Belle de Jour" is an expression translating literally as "beauty of [the] day," as opposed to "femme de nuit" or "belle de nuit," women of the night (common references to prostitutes). "Belle de jour" is a play on the phrase, possibly a reference to the daylight rendezvous made by some call girls, including Belle de Jour herself.

There was speculation in the media for several years as to the real identity of the author, whether Belle really was a call girl and whether her diary entries were based on fact or entirely fictitious. Guesses as to who Belle was ranged from Rowan Pelling to Toby Young according to The Telegraph.

According to The Guardian a fellow British blogger guessed her identity in 2003 but kept it secret. He made a page on his blog containing the googlewhack of Belle de Jour and Brooke Magnanti that allowed him to see if anyone googled the two names. In 2009 he identified IP addresses originating from Associated Newspapers that had accessed the page at which point he contacted Brooke to alert her.

Revelation of identity

On 15 November 2009, The Sunday Times revealed in an interview that Dr Brooke Magnanti is the author's real name; Magnanti was 34 years of age at the time. The Guardians Paul Gallagher described it as the revelation of "one of the best kept literary secrets of the decade". The Daily Telegraphs Stephen Adams said it had been "the new millennium's equivalent of the 1980s' search for the golden hare". Such was the nature of the secret, Magnanti's work colleagues did not know until one month before she went public, her publishers had been unaware of her true identity until the previous week and her parents found out on that weekend. After signing her first book deal and starting writing articles for newspapers, only two other people were aware of her identity, her agent Patrick Walsh and her accountant, who handled the financial transactions via a shell corporation. Magnanti commented that she had thought a former boyfriend was on the verge of outing her.

Writing on her blog on the day of the revelation, Magnanti stated:

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. 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

A spokesperson for Bristol University stated, "This aspect of Dr Magnanti's past is not relevant to her current role at the university", while her publisher said, "It's a courageous decision for Belle de Jour to come forward with her true identity and we support her decision to do so".

Since unveiling her identity as Belle de Jour, images of Brooke Magnanti appeared in several national newspapers.

Diary of a London Call Girl

Magnanti says she worked for 14 months as a £300-an-hour prostitute for a London escort agency in 2003, while she was writing her PhD thesis. She did so due to lack of funds during her studies at the University of Sheffield in 2003.

Her story found its way onto a blog, having previously been a science blogger. Diary of a London Call Girl was voted Blog of the Year by The Guardian newspaper in 2003.

Later work

Belle has always maintained that she is who she claims to be and her publisher, Orion Books, continues to print her first two books as part of its "Non Fiction/Memoir" line. Her third book, however, has been classified as fiction and purports to represent a fictional continuation from the first two. From November 2005 until May 2006, Belle contributed a regular column in The Sunday Telegraph. On 25 February 2010 Magnanti appeared on the BBC political affairs programme This Week to discuss the subject of sex education.

Scientist

After her pseudonymous publishing career Belle was identified as a research associate in developmental neurotoxicology and cancer epidemiology at the Bristol Initiative for Research of Child Health (BIRCH), part of Bristol University's Centre for Nanoscience and Quantum Information. Specifically she has researched a possible link between the occurrence of thyroid cancer in women in Cumbria and fallout from Chernobyl in Ukraine and also the policies for assessing the risks of organophosphates.

Novelist

Belle is currently writing a novel, due to be published in 2012.

A television series loosely based on the first book was in development with Channel 4 in the UK, but eventually aired on ITV2 as Secret Diary of a Call Girl. The first series aired from 27 September 2007 to 15 November 2007 starring Billie Piper as Hannah Baxter (Belle). It is now being shown in the US on Showtime. Piper met Magnanti in the course of preparing for the role but maintained her pseudonymity. A half-hour TV programme covering a meeting and conversation between the two was broadcast on ITV2 on 25 January 2010. The second series commenced broadcasting in the UK on ITV2 on 11 September 2008.

The third series began broadcasting in the UK and North America in January 2010. The fourth and final series is now in production.