UK- With the intellect to win a place at Oxford at the age of 13, Sufiah Yusof should, by now, be carving out a high-flying career for herself.

But a decade after hitting the headlines thanks to her remarkable aptitude for mathematics – and days after her father was jailed for sexually assaulting two teenagers – Miss Yusof has been exposed as a £130-an-hour prostitute.

The revelation completes a sad fall from grace for the family who were hailed the brightest in Britain after Miss Yusof and two of her siblings won university places by the time they were 16.

Calling herself Shilpa Lee, 23-year-old Miss Yusof advertises her body on an internet sex site and operates out of a back street flat in Salford. Yesterday, a friend of the former child prodigy said of her downfall: “It is all desperately heartbreaking.

“With her amazing brain she should be able to make money any way she wants. But instead her life spiralled completely out of control.

“Sufiah has suffered so many knocks in her life. I just hope she can drag herself out of this life she has got herself into.

“She is such a good person and deserves a much better life than this. Her gift really has been a curse.”

On the website, she describes herself as a ‘”very pretty size 8, 32D bust and 5ft 5in tall – available for booking every day from 11am to 8pm”.

She adds that she is a “sexy, smart student” who prefers “older gentlemen”. When an undercover reporter visited her at the flat, Miss Yusof stripped naked and gyrated on a bed as she reeled off her list of services.

Miss Yusof was pictured as a child smiling innocently outside St Hilda’s College, Oxford, after winning her place to study maths in 1997. But she ran away three years later, aged 15, claiming her parents had placed her under intolerable pressure to succeed.

She was found by police 12 days later working as a waitress at a Bournemouth internet cafe but refused to return to her parents, who had given up their jobs to educate their five children at home.

Miss Yusof was taken in by a foster family and shortly afterwards sent a searing email to her parents, documenting the “living hell” she said her father – a private tutor – had created.

She wrote: “I’ve finally had enough of 15 years of physical and emotional abuse.”

She accused her “controlling and bullying” father of forcing her to work in the cold to aid concentration and added that she never wanted to see him again.

In 2004, she married trainee lawyer Jonathan Marshall, but the couple divorced 13 months later.

In January, the Daily Mail revealed that her father Farooq had been remanded in custody after admitting sexually assaulting two girls, both aged 15.

Appearing under his real surname of Khan, he was jailed for 18 months at Coventry Crown Court last week after a judge heard how he had groped the two girls when he was home tutoring them at maths.

He had previously been jailed for three years in 1992 for his part in a £1.5million mortgage swindle involving several family members.

Yesterday the News of the World described how Miss Yusof was armed with three mobile phones as she welcomed an undercover reporter who was posing as a client at her flat.

The once strict Muslim stripped out of her tiny skirt, leather boots, tight T- shirt and red matching underwear as she detailed her £130-an-hour rate.

She claimed to be studying for a masters degree in economics on a part-time two-year course in London and added: “I’ve got exams coming up and I’m thinking, ‘Oh my God!’.”

Yesterday, her mother, Halimahton, 51, a scientist, said she had no idea her daughter was working as a prostitute.

Speaking from her home in Coventry, Mrs Yusof said: “I didn’t know anything about that. I am not in touch with Sufiah any more. I have got no comment.”

Miss Yusof’s brother, Iskander, aged 12, and sister Aisha, 16, started at Warwick University in 1998, making them the youngest brother and sister to study together at university at the time.