Nigella Lawson was accused by former husband Charles Saatchi of being "off her head on drugs" and was addicted to cocaine and cannabis, which she took "every day for a decade."
He also accused her in an email of poisoning her daughter and trashing her own life.
The claims were revealed as a judge said that the trial of Italian sisters Francesca and Elisabetta Grillo could go ahead. The sisters are accused of fraud while working for the now-divorced celebrity couple,
The Isleworth Crown Court in west London was told on Wednesday that the marriage of British television chef Nigella Lawson and art tycoon Charles Saatchi was dominated by a "culture of secrecy." This enabled her to hide her alleged drug abuse..
Lawyers acting on behalf of the sisters had argued that the case should be dropped because Lawson's alleged drug use damaged her credibility as a witness.
Anthony Metzer, representing Elisabetta Grillo. said:
The defendants' case is that Nigella Lawson lied to her ex-husband about her drug use and about the expenditure that was incurred by the defendants, both expressly and implicitly, because she was fearful of Mr Saatchi's reaction if he knew about the extent of the expenditure and drug use. There was a culture of secrecy within Nigella Lawson's marriageMetzer accused Nigella and Saatchi of attempting to manipulate the court process, and therefore the Grillo sisters would not receive a fair trial. He continued:
It's a convenient forum for Mr Saatchi and Miss Lawson to rehearse disputed issues between them... in the criminal courts where, of course, the possibility of libel is not possible," he said. If Mr Saatchi is telling the truth, then Miss Lawson is a habitual criminal.But Judge Robin Johnson did not accept this argument and ruled that the trial should go ahead.
"I consider, with the right rulings and the ability to monitor the process of the court during the process of the trial, a fair trial can be achieved and therefore I have refused this application," he said.
The court saw documents from Saatchi on Tuesday in which he called Lawson "Higella," and alleged she was so "off her head" on drugs that her assistants were able to go on spending sprees with her credit card.
Multimillionaire art collector Saatchi, 70, and Lawson, 53, who has made her own fortune with TV shows in Britain and the United States, got divorced earlier this year after 10 years together.
The incident which triggered the path to divorce occurred in a London restaurant, where Saatchi was pictured holding Nigella by the throat during what appeared to be a heated argument. Saatchi was cautioned by the police over the incident.
Nigella Lawson is the daughter of Nigel Lawson, who was the finance minister in Margaret Thatcher's government. She is expected to give evidence during the trial.
Charles Saatchi, together with his brother Maurice, built one of the most successful advertising agencies of the 1970s. Their campaign on behalf of the Conservative party was credited with enabling Thatcher to come to power. Charles now owns London's Saatchi Gallery of contemporary art. He married Nigella Lawson in 2003.
She has two children from her marriage to journalist John Diamond, who died of throat cancer in 2001. Saatchi has one daughter from his previous marriage.