DAY IN COURT: What began as the London fraud trial of the two former personal assistants of Charles Saatchi and Nigella Lawson has rapidly turned into live theater where the drama of the couple’s turbulent marriage is playing out in minute detail.

Lawson arrived in court with impeccable hair and make-up, dressed in black and with her head held high. She gave evidence in a criminal case against the two Italian sisters at London’s Isleworth Crown Court on Wednesday and took the opportunity to let loose on Saatchi.

According to press reports, she described her ex-husband as “a brilliant and brutal man,” by whom she felt “subjugated to intimate terrorism.” The couple divorced earlier this year following the publication of photos showing Saatchi grabbing his wife by the throat while the two were dining outside at Scott’s in Mayfair.

She also admitted to taking cocaine on a handful of occasions answering allegations that had emerged in the court last week. However, Lawson denied accusations that she is an addict. “The idea that I’m…an habitual user of cocaine is absolutely ridiculous. I did not have a drug problem, I had a life problem,” she told the court. She also alleged that Saatchi is “on a campaign to ruin me in any way.”

Last week Lawson’s name dominated headlines in the U.K. after emails linked to the case emerged. In the emails, Saatchi accused her of being an habitual cocaine user.

According to press reports, Saatchi’s email had said Francesca and Elisabetta Grillo, would escape prosecution for allegedly spending hundreds of thousands of pounds of Saatchi’s money on designer goods and other luxuries for their personal use, because Lawson had allowed the spending while under the influence of drugs.

When she took to the witness stand, Lawson said she felt as if she was on trial, at one point calling the process “a witch hunt.”

“I am called to answer, and glad to answer the allegations, and the world’s press… It comes after a long summer of bullying and abuse,” Lawson was reported as saying in reference to Saatchi.

During the trial, Lawson admitted to taking cocaine on six occasions with her husband John Diamond, who died of cancer in 2001, and once in 2010, when she was having a “very difficult time” in her marriage to Saatchi.

She also admitted to smoking cannabis, as “it made an intolerable situation tolerable.” But she said of the drug: “It is a false friend and [taking it is] not a good idea. I found the answer was in changing the situation and trying to create a tolerable situation for me and my family.” She added that she was now free of “any drug.”

Saatchi gave evidence last week, most notably saying that he was “bereft” that the emails between him and Lawson had become public and saying that he still “adored” his ex-wife. He also said he had no proof that Lawson had ever taken drugs.

After being cross-examined by Elisabetta Grillo’s defense attorney, Lawson will return to court on Thursday to be cross-examined by Francesca Grillo’s lawyer.