A disgraced racing tipster who sexually assaulted his Brazilian au pair just days after she landed in the country was today beginning two years behind bars.

Kevin Booth, pictured, a maths teacher-turned successful racing entrepreneur, has swapped his luxury home - complete with swimming pool and tennis Court - for a prison cell after a jury at Bradford Crown Court rejected his claims that the 27-year-old woman had consented to their sexual encounter.

The jury took just over an hour to find 41-year-old Booth guilty of indecently assaulting the au pair behind locked doors at his offices in the grounds of Broughton Hall, near Skipton, in April last year.

But it was only after their verdict had been returned that it was revealed that the former proprietor of a private school in Northumberland had been given a suspended prison sentence in 1994 for "punishment" assaults on pupils with sticks or canes.

During Booth's five-day trial the jury heard how the au pair, who had answered an advert he placed on the internet, was taken to the offices of Isiris Racing Services, just two days after arriving in this country.

She described how Booth gave her a list of rules and duties and also showed her a video in which he was seen to whip a naked woman on the buttocks with a riding crop.

The next day she again went to the offices and after Booth's secretary had gone home he put on some music, closed the blinds and used her Portuguese-English dictionary to try to get his victim to massage him.

During the terrifying encounter, Booth offered the woman money for sex and she told the jury that at one point she thought he was going to rape her. She refused to take part in oral sex with him, but during the incident he indecently touched her.

A few days later the woman sought help from Booth's secretary when she feared that he was going to "horse-whip" her at the offices as punishment for refusing to have sex with him.

Booth denied any kind of sexual contact with the woman when he was arrested by police, but DNA tests later linked him to semen found on her T-shirt.

In court he claimed that the au pair had been "flirting" with him, but he had lied about the sexual encounter because he didn't want his current 20-year-old partner, Tammy, to find out.

After the jury's guilty verdict Booth's barrister Timothy White said his racing business would inevitably collapse and he would have to use his savings to pay back clients who had invested money in it.

"He is not a man who will find the prison environment easy to bear - exactly the opposite," he said. "He will be a very vulnerable prisoner and imprisonment will bear down very hard on him."

Judge Peter Armstrong yesterday sentenced Booth, of Hollins Lane, Utley, near Keighley, to two years in prison and ordered him to pay the prosecution costs of £6,850.

He told the divorcee that his victim should have had an enjoyable experience working for his family and learning English.

"Far from having an enjoyable experience you subjected her to a most unpleasant indecent assault," he said. "The only thing that can be said in your favour is that you did not persist beyond that which she says occurred.

"You lied through your teeth to the police."

Judge Armstrong added that a substantial sentence was necessary not only to deter Booth from committing such offences again but also to deter others who may think that the internet was an easy way to get au pairs on which to "slake their lust."