Nigella Lawson's told a court she's taken cocaine twice in her life.
The TV chef says claims she was an addict are "absolutely ridiculous".
She's been giving evidence in the fraud trial of two of her former assistants, who say they were allowed to spend what they liked on credit cards to keep her habit a secret.
Nigella admitted she has taken cocaine several times - including when being subjected to "intimate terrorism" by her ex-husband Charles Saatchi.
The TV cook's also revealed smoking cannabis occasionally - but has "never been a drug addict or abuser".
Wearing black, staring straight ahead and flanked by 7 police officers, Nigella Lawson faced dozens of photographers and reporters from around the world as she arrived at Isleworth Crown Court.
This afternoon she admitted taking cocaine on two occasions.
The first time was when the 53 year old's late husband John Diamond found out he had terminal cancer.
The second she says - during difficulties in her second marriage to ex-husband Charles Saatchi
Ms Lawson also admitted taking cannabis in the last year of her marriage to Mr Saatchi.
But she insists she is now free of drugs - she told the court:
"I have never been a drug addict. I've never been a habitual user."
And later in her evidence she said
"I have to say, since freeing myself from a brilliant but brutal man, I'm now totally cannabis, cocaine, any drug-free."
Earlier she accused her ex-husband Mr Saatchi of trying to destroy her.
The pair's former PAs, Francesca and Lisa Grillo are on trial - accused of spending nearly 700-thousand pounds on cards loaned to them by the TV chef and her ex-husband.
The sisters claim they were allowed to use credit cards in exchange for covering up the TV star's drug use.
The trial continues.
