It has been alleged, by Francesca Grillo – Nigella Lawson’s former aide, currently accused along with her sister of fraudulently spending £685k while under employment– that the TV chef would stay up all night, using cocaine and writing cook books. The startling new accusation comes after weeks of claims that Lawson was a regular user of cocaine and marijuana for various parties.

Nigella LawsonNigella's supposed drug use has hit the headlines since the courtcase began

Francesca told the court Nigella was “absent and grumpy”, blaming her mood swings on a lack of sleep.

She said: “At the beginning of 2012 there were a few episodes where she came down and she had white powder inside her nostril. A few times I ignored it but other times I told her and she said ‘it’s just make-up’. It was too white to be make-up.” (The Mirror)

Francesca Grillo is on trial alongside her sister Elisabetta, both of whom are accused by Lawson and her ex-husband Charles Saatchi of spending money on the company account without permission.

“When she was writing a new book she said she needed to work through the night because she found it easier and she needed help to stay up all night,” added Franseca to the court. “She had a runny nose for a long period of time, and at a strange time, in the summer.”

Crucially, Francesca admitted to never seeing Nigella use cocaine, and while she asserts that Nigella also started using marijuana, she couldn’t confirm if the “remnants” she saw were her’s or her kids’.

“The cannabis started later when we moved into the new house. There were signs. I remember sometimes after some dinner parties there were remnants in the kitchen. I can’t say if they were her’s or the children.”

Nigella Lawson trialLawson remains as national favourite as her fans stick by her

The court heard that Francesca allegedly travelled around Europe in 2011, visiting Prague, Milan, Amsterdam, Rome, Berlin, Paris, Ibiza, and Antwerp, and that she spent £1,100 during one dinner at the Four Seasons restaurant in Paris in June 2011 and then another £3,500 on two hotels in New York.