Media playback is unsupported on your device Media caption The BBC's Luisa Baldini was inside court when Ms Lawson admitted taking cocaine

TV cook Nigella Lawson has admitted taking cocaine, but denies having a drug problem or being an addict.

She said 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 her ex-husband, Charles Saatchi.

She made the admission at the trial at Isleworth Crown Court of her former assistants, who deny fraud.

Francesca and Elisabetta Grillo's defence claims Ms Lawson allowed them spend on credit cards in return for covering up her drug use.

Ms Lawson, 53, said she took cocaine with Mr Diamond on six occasions, after he found out his cancer was terminal.

"It gave him some escape," she said.

She said she had responsibility for looking after him and the family as well as earning a living - and that she had spoken to a doctor at the time.

Image caption Nigella Lawson said she was not a "habitual drug user"

She went on: "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.

Ms Lawson added it "completely spooked" her.

"The idea that I am a drug addict, or habitual user of cocaine is absolutely ridiculous."

'Grabbed by the throat'

Ms Lawson said Mr Saatchi "told everyone" he was taking cocaine out of her nose after he was photographed holding her neck at Scotts restaurant.

She claimed the incident was actually sparked when she commented on a person walking past with a baby.

"I said 'I'm so looking forward to having grandchildren'."

"He grabbed me by the throat and said 'I'm the only person you should be concerned with'."

Image caption Elisabetta (left) and Francesca Grillo both deny fraud

Ms Lawson told the court she smoked cannabis in the last year of her marriage to Mr Saatchi.

"I found it made an intolerable situation tolerable. It's a false friend and not a good idea.

"I have to say, since freeing myself from a brilliant but brutal man, I'm now totally cannabis, cocaine, any drug-free."

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," she added.

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," she said.

"I felt by going to my GP I didn't feel a need to tell him."

Ms Lawson said Elisabetta was aware she had taken cocaine in the past, but said claims that credit cards and envelopes containing white powder were left around the home she shared with Mr Diamond were "completely false".

She admitted that Mr Diamond used rolled-up notes to take the drug.

"John did but he carefully ironed them out," she said. "There is some misery you cannot escape."

Ms Lawson said she was not a "habitual drug user and drug addict, or a snorter of cocaine for 10 years".

Asked by Anthony Metzer QC, representing the Grillo sisters, where the drug claims may have come from, Ms Lawson replied: "I believe some of it came from your clients and Mr Saatchi - not the three most reliable witnesses."

'Witch hunt'

Ms Lawson said she believed Mr Saatchi was on a campaign to "ruin me in any way", whether financial or otherwise, and had a mindset of "get her, I don't care what it takes".

Image caption Charles Saatchi sent an email to Ms Lawson claiming she had taken drugs

"I think he likes everyone to do what he wants," she said.

Ms Lawson said there was a "witch hunt" against her and that she felt like she was on trial with no counsel and "no rights".

Earlier in the trial, jurors were read an email to Ms Lawson from her former husband in which he alleged that she had taken drugs.

In response, she described the allegations as being "part of his plan of attack".

She said she had hidden any drug use from Mr Saatchi, adding: "I could have weathered a conversation about it, I just wouldn't have wanted to."

Ms Lawson is to return to court on Thursday to complete her evidence.

The case continues.