Cowell is said to have met the girl in Hollywood nightclub Drai's and taken her back to his hotel, according to The Sun.

He awoke to find his wallet and laptop missing. Cowell called the police to track down the device, which contained secret information about his TV shows.

The woman allegedly agreed to return the computer, but kept money from the supremo's wallet.

The claims surrounding the theft are just a few of the revelations stemming from Bower's new book, due to hit shelves on Friday.

A separate story in the Daily Star newspaper today alleges that Cowell was secretly engaged to Page Three girl Louise Payne, after she split from husband and Right Said Fred star Fred Fairbrass.

But their three-year relationship ended when the buxom blonde said she wanted to start a family with Cowell, but he was too busy.

Cowell apparently popped the question to the now-43-year-old in a lift during a business trip to New York, reported the Daily Star.

A source told the newspaper: 'Simon was heartbroken. They tried to make it work but it all went wrong.'

The pair met at a function in London in in 1995, after the end of Louise's marriage to guitarist Fred, now 55.

They allegedly first exchanged numbers at the party which Cowell was attended with his brother Nicholas.

But during their first date, he had the flu and thought he had blown his chances. A year later they bumped into each other and began a romance.

The source added: 'The relationship had its ups and downs. They split twice but he was so in love with her he kept trying to make it work.

'After the third attempt, they split for good. It was just before he started on Pop Idol. Louise wanted kids and he knew he wasn’t ready.
'He never stopped loving her, though. He was heartbroken.'
The revelation comes as Bower reveals a string of claims about Cowell's previous escapades, including a short fling with fellow X Factor judge Dannii Minogue.
He is quoted as saying he felt 'genuine love' for the brunette. The Australian has not commented on the claims.
Cowell's string of girlfriends also include former Page Three girl Jackie St Clair, 48, model and lap-dancer Georgina Law, 31, model Jasmine Lennard, 26, 1980s pop star Sinitta, 48, and TV presenter Terri Seymour, 38.
He has never been married but in 2010 he proposed to make-up artist Mezghan Hussainy, 38.
But their relationship ended in September last year.

Cowell is said to have proposed to Idol makeup artist Mezghan on Valentine’s Day with a £250,000 ring.
And after their split, he agreed to transfer the ownership of his £5million hill-top house in Beverly Hills to her, according to the book.
To add further fuel to the fire, revelations of Cowell's early disdain for Gary Barlow have surfaced.
He initially found the Take That star so dull, he considered sacking him as X Factor head judge.
Simon said: 'At first Gary appeared to be a bit stiff. But he grew in confidence and stature.
'I was nervous about the panel full stop at first - but I've re-signed them all.'
This year will see the introduction of Facebook auditions, whereby contestants can upload videos and successful applicants will be invited to perform for the panel.


Read more: dailymail