LONDON — Nigella Lawson is a “habitual” cocaine user who “trashed” her daughter’s life by allowing her to take drugs, a court has heard.

The TV chef’s use of cocaine, Class B drugs and prescription pills on a “daily” basis for more than a decade was part of the reason for her infamous bust-up in a Mayfair restaurant with her husband Charles Saatchi, which led to their divorce.

Saatchi said he was “completely astounded” by the scale of her alleged drug use in a statement read out in court on Tuesday. He referred to her as “Higella” in an email to her and said she and her 19-year-old daughter Cosima, known as Mimi, were “off (their) heads on drugs”.

The allegations came to light when a judge at a London court ruled that two former aides of Lawson could use her “bad character” as part of their defence against charges that they defrauded the couple out of more than £300,000 (S$609,000) using a corporate credit card.

Francesca, 41 and Elisabetta Grillo, 35, claim Lawson, 53, allowed them to spend the money on holidays and designer goods on the understanding that they kept her “guilty secret” from Saatchi. The Italian sisters, described by Lawson as her “kitchen confidantes” are due to stand trial this week. Following the judge’s ruling, Lawson, who is a witness in the case, will be cross-examined about her alleged drug use.

Judge Robin Johnson had previously ruled the “bad character” evidence inadmissible, but he changed his mind after the prosecution disclosed more than 100 pages of new material on the eve of the trial, including an email from Saatchi to his ex-wife.

In the email, Saatchi wrote: “Of course, the Grillos will now get off on the basis that you and Mimi were so off your heads on drugs, you allowed the sisters to spend whatever they liked. And yes, I believe every word the Grillos have said, who, after all, only stole money. You, Higella, on the other hand, poisoned your child with drugs and trashed her life. Classy!”

The judge also lifted a reporting restriction that had until now prevented any publication of the allegations. Summarising the defence case, Judge Johnson said: “Miss Lawson is a user of Class A and Class B drugs on a daily basis, this was a guilty secret kept from her husband ... I will allow questions to be asked of Miss Lawson and other witnesses as to the alleged use of drugs and prescribed drugs.”

A prosecutor said Lawson had described the allegations as “totally scurrilous” and untrue. “The timing is no coincidence at all.”

She said that despite being arrested more than a year ago and charged in March this year, the sisters only made the drug allegations to the court earlier this month.

A spokesperson for Lawson said: “As proceedings are live, we cannot comment at the moment.” THE DAILY TELEGRAPH