Sisters Francesca and Elisabetta Grillo arrive at Isleworth Crown Court in west London CREDIT: REUTERS

The Italian sisters who once worked for Nigella Lawson have talked about her mood swings and how she binged on junk foods.

In their first interview after they were cleared of the fraud case against them, Francesca and Elisabetta Grillo spoke to The Daily Mail about working with their former employers, TV Chef Nigella Lawson and her Ex-husband Charles Saatchi. The sisters claimed that Lawson has been 'highly erratic and irritable' when she became dependent on cocaine.

"She'd always been a warm caring person but in the last few years she was very grumpy and moody. She'd make excuses, blaming a lack of sleep and the cares of motherhood," Francesca said.

They also revealed that Lawson has been suffering from insomnia and would have frequent changes in energy levels.

"She'd be this hyperactive Duracell bunny buzzing round the house. But then she wouldn't be able to sleep and would turn into a zombie. When you spoke to her it was like there was nothing there. She was vacant," Francesca added.

The sisters also talked about Lawson's binge-eating problem when she was dealing with her collapsing marriage. Elisabetta, in particular, mentioned how she would eat "two big chocolate bars a night."

Meanwhile, the British police is set to review the evidence suggesting that the TV chef is using cocaine, including Lawson's court admission on her drug use.

The Metropolitan Police said in a statement that a specialist team will examine "all the evidence emerging as part of a review into this matter and in conjunction with the Crown Prosecution Service, will determine an appropriate way forward."

The statement came as a clarification after the police previously decided not to investigate Lawson's drug use.

"The senior investigating officer received legal advice that the witness's admissions did not by themselves provide sufficient evidence to bring charges," the statement said.

"On that basis therefore, and in absence of any other corroboration, there is no imminent prospect of a prosecution being mounted," it added.