Nigella Lawson has confessed she has taken cocaine ''several times'' but has denied allegations she is a regular user.

The TV chef admitted she had used the illegal drug whilst giving evidence at Isleworth Crown Court in London today (04.12.13) in the ongoing fraud trial against her former assistants Elisabetta and Francesca Grillo - who are accused of spending £685,000 on a credit card belonging to Nigella and her ex-husband Charles Saatchi.

Nigella admitted to using the drug with her late first husband John Diamond on six occasions in the wake of his diagnosis with terminal throat cancer in 1997 and again in 2010 when she claims she was subjected to ''intimate terrorism'' by Charles.

Nigella - who admitted to smoking cannabis in the final of her marriage to Charles - said: ''I have never been a drug addict. I've never been a habitual user. There are two times in my life when I have used cocaine. I have to be honest, I have smoked the odd joint. 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.''

Speaking about the most recent occasion she took cocaine, the TV chef revealed: ''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.''

Nigella totally dismissed allegations she took cocaine on a daily basis and was a drug addict, branding the claims ''absolutely ridiculous''.

The 'Nigellissima' star also revealed her former assistant's alleged credit card fraud ''broke her heart''.

She shared had a close friendship with Elisabetta and was ''flabbergasted'' to discover the extent of her and her sister's spending.

She said: ''It was very difficult when I found out that someone who I trusted has behaved in that way. In my heart of hearts I did not believe her to be a bad person.''

The 53-year-old star explained how she employed Elisabetta, 41, 16 years ago and revealed the aide was a ''rock'' to her following the death of her husband John in 2001.

She said: ''She came to me at a very difficult time in my life and she was a rock and I would have done anything for her.

''Sometimes I had to rush to hospital, she would stand in. She was my rock. I will never forget what she did for my family.''

Nigella confirmed that the sisters were issued company credit cards, which were not to be used for personal expenses. The Grillos previously claimed the TV chef had given them permission to spend as they pleased so they wouldn't reveal her alleged drug habit - which she also denied - to Charles, 70.