Celebrity British chef Nigella Lawson has admitted taking cocaine, but denies having a drug problem or being an addict.
The 53-year-old told a court on Wednesday that she had first taken the drug with her late husband John Diamond when he was terminally ill.
Ms Lawson said she had taken it again in July 2010, after she felt she had been "subjected to intimate terrorism" by former husband Charles Saatchi whom she divorced earlier this year.
She made the admission at the trial at Isleworth Crown Court of her former assistants, two Italian sisters accused of fraudulently spending £685,000 on credit cards.
The BBC reports the defence for Francesca, 35, and Elisabetta Grillos, 41, claims Ms Lawson allowed them spend on credit cards in return for covering up her drug use.
Ms Lawson said she took cocaine with Mr Diamond on six occasions after he found out that his cancer was terminal.
"It gave him some escape," she said, adding that she had spoken to a doctor at the time.
"There was another time I took cocaine. In July 2010 I was having a very, very difficult time. I felt subjected to intimate terrorism by Mr Saatchi," she said, adding that she felt "isolated and in fear of ... just unhappy".
"A friend of mine offered me some cocaine, I took it," she said, adding that it "completely spooked" her. "The idea that I am a drug addict, or habitual user of cocaine is absolutely ridiculous."
Ms Lawson said Charles Saatchi "told everyone" he was taking cocaine out of her nose after he was photographed holding her neck at Scotts restaurant earlier this year.
Ms Lawson also told the court that she smoked cannabis in the last year of her marriage to Mr Saatchi. She said she did not know how to roll a cannabis joint but had asked others in her house to do so. "This was not behaviour I'm proud of."
Mr Saatchi was unaware that she was smoking cannabis, she told jurors, before admitting that she had not told him that she had taken cocaine once during their marriage. "It was a one-off."
Earlier, Nigella Lawson said Charles Saatchi wanted to get revenge after she refused to back him over paparazzi pictures that showed him gripping her by the throat at Scotts restaurant.
She said the allegations that have been made about her at the trial had followed "a long summer of bullying and abuse. I have been put on trial here where I am called to answer, and glad to answer the allegations, and (in) the world's press."
Ms Lawson said she had been reluctant to give evidence in the trial. "He had said to me if I didn't get back to him and clear his name, he would destroy me," she said.
On Friday, Mr Saatchi told the court that he had "no proof" that Ms Lawson had ever taken drugs.
The couple divorced in July after 10 years of marriage. Mr Saatchi was earlier cautioned for assault after images of him grasping Ms Lawson by the neck at the London restaurant appeared in a newspaper.
Ms Lawson told the court that Elisabetta did not have a strong moral compass, but she did not believe her "to be a bad person". She was a "stalwart" who had helped her through the death of John Diamond.
Ms Lawson said the accusations of fraud "broke our heart" when they were revealed to her and Mr Saatchi.