Charles Saatchi referred to his former wife Nigella Lawson as "Higella" and accused her of being so affected by drug use that she allowed their personal assistants to spend the couple's money on whatever they liked, a court has heard.

Italian sisters Francesca and Elisabetta Grillo are due to go on trial accused of committing fraud while they worked as PAs to the celebrity couple.

Today, ahead of the case being heard at Isleworth Crown Court in west London, Judge Robin Johnson read out an email sent from Saatchi to Lawson following their high-profile divorce earlier this year.

In the email, Saatchi said: "Of course now the Grillos will get off on the basis that you ... were so off your head on drugs that 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."

The millionaire art dealer called his ex-wife "Higella" in the email, which was sent on October 10, and signed off "Classy!", the court heard.

Judge Johnson said that when Saatchi was asked by police to explain what he meant in the message, he said: "I can't remember precisely what I had in mind. On reflection I was simply speculating that the sisters would use this information to defend themselves."

The pair broke up after pictures were published in a newspaper in June showing Saatchi holding his wife by the throat at a restaurant.

The incident was dismissed by Saatchi as nothing more than "a playful tiff" but he later accepted a police caution for assault.

Anthony Metzer, QC, defending Elisabetta Grillo, told the court yesterday that Saatchi had told lawyers he did not know about Lawson's alleged drug-taking during their 10-year marriage and only found out as they were splitting up.

Elisabetta, 41, and Francesca Grillo, 35, of Bayswater, west London, both deny the charge against them. Referring to the ­defendants, Mr Metzer added: "Our clients have been the innocent pawns in a rather unpleasant battle going on between Mr Saatchi, Miss Lawson and their lawyers. We come within the parameters of manipulation of the court."