Belle de Jour named

For weeks the literary world has been kept guessing as to the identity of a prostitute whose web diary, written under the name Belle de Jour, attracted a worldwide cult readership.

The writer's sexual frankness, which appeared to lay bare a world of loveless sexual encounters and cash exchanges, has garnered both shock and praise.

But now a literary detective claims he has identified the person behind the Belle de Jour diary through a close analysis of her writing style.

The weblog writer's rise to literary stardom, which had appeared to guarantee a major book deal, could be blocked by revelations she is not in fact a London call girl but a 33-year-old previously published author from Manchester.

Don Foster - the man who unmasked Joe Klein as the author of the Bill Clinton satire Primary Colours - claims Belle is in fact Sarah Champion, a little-known writer, sometime publicist and occasional compiler of drum 'n' bass CDs.

Mr Foster studied Belle's use of collective nouns, hyphens, brackets, italics and compound verbs, ran these through the internet search engine Google and managed to pinpoint similar examples of the style under Champion's name.

"While no piece of evidence is conclusive by itself, I'm sure we have found the woman," he said.

Ms Champion herself remains enigmatic. Speaking from California, where she is living with her boyfriend, she did not deny being Belle, but added, laughing: "I'm in San Francisco at the moment - to hide. How did you find my name? Give me a clue."

She later sent The Times newspaper an email stating: "I want to make clear that I have never been a call girl." But Ms Champion-has been many things. She grew up in Manchester, but quit school before doing her A-levels to start freelance writing for the New Musical Express and the Manchester Evening News.

In the mid-Nineties she published anthologies about the alternative music scene, such as And God Created Manchester and Disco Biscuits. She left Britain in 2000 for Bangkok, returning in 2002. She has been described as a "global party correspondent, private detective and former publicist".

However, she does share some characteristics with Belle. They both have a passion for obscure bands, have spent time in Manchester, are widely read in contemporary literature and show a detailed knowledge of south London. In 2002 Ms Champion was living in West Norwood, less than a mile from the A23, which Belle describes as separating her from her boyfriend.