One of the personal assistants accused of defrauding Nigella Lawson and Charles Saatchi has told a court the TV cook allowed their children to smoke cannabis.
Elisabetta Grillo, 41, who also accused the celebrity couple of lying under oath, told jurors Ms Lawson permitted the teenagers to smoke the Class C drug as she gave evidence in her fraud trial.
The defendant, who along with her sister Francesca Grillo, 35, is accused of spending £685,000 on credit cards belonging to the celebrity couple to buy designer goods and luxury holidays for herself, made the allegations as she spent a second day in the witness box at Isleworth Crown Court in west London.
Elisabetta, 41, was asked by prosecutor Jane Carpenter to explain a duty-free transaction for £69.71 in New York in June 2010.
"It was cigarettes for the children. I bought them and Nigella allowed me to buy them," Grillo said.
"I don't remember how many packs. Nigella always told me to buy it."
Asked by Ms Carpenter: "What on earth did you think you were doing, buying cigarettes for underage children?"
Grillo said: "Well, if Nigella Lawson let the children smoke weed..."
The defendant tailed off as Judge Robin Johnson interrupted the exchange.
Grillo told the court that Mr Saatchi only discovered his former wife's alleged drug habit on the day he was photographed with his hands around her throat outside Scott's restaurant in Mayfair, central London.
Jurors were told Grillo had not originally planned to use her former boss's alleged drug taking in her defence in an effort to protect the TV cook.
An original defence case statement for Elisabetta Grillo from August did not include allegations of Ms Lawson's drug use because she did not want them raised in court out of a "remnant of sympathy" for her, jurors heard.
But an extra statement added in November did include the claims.
The additional statement, read to the court by Elisabetta Grillo's barrister Anthony Metzer QC, said: "The defendant will assert that the prosecution witness Nigella Lawson habitually indulged in the use of Class A and Class B drugs in addition to the abuse of prescription drugs throughout the time that the defendant was employed in the household.
"This evidence is of substantial importance as it explains why Ms Lawson initially consented, or appeared to consent, to the expenditure as the defendants were intimately connected to her private life and were aware of the drug use which she wanted to keep from her then-husband Charles Saatchi.
"The defendant's case is that Ms Lawson's drug use and the defendant's knowledge of it materially affected her attitude to the defendant's spending and in turn her attitude to this prosecution.
"Whilst it is not the defendant's case that there was an explicit agreement for silence in return for aquiescence in expenditure, the intimate atmosphere created by such knowledge informed their relationship and what the defendant considered was permitted by Ms Lawson."
The statement said the defendant suggested the reason why Ms Lawson had maintained she did not consent to the spending was because of her "fear of Mr Saatchi" and concern that he would think the spending had been allowed, either expressly or implied, by Ms Lawson because her drug use could be exposed.
The court heard that Grillo had told her solicitors about the issue but did not originally want it in her defence case because she felt a "remnant of sympathy towards Ms Lawson" and so did not want it to be raised in court.
But the statement added: "On mature reflection, given that this illicit use of drugs goes directly to her defence of actual or implied consent, she now expressly instructs that this matter should be raised to ensure fairness in the proceedings."
Asked about the now-famous incident outside Scott's, Italian-born Grillo said this was when she and her sister decided to bring up the drugs allegations.
She told the court: "I think especially when Charles picked her nose, it was the proof she still took drugs and he discovered that day.
"So we then decided it was the moment for everybody to know the truth - she could lie easily."
She said before this she had wanted to "protect" Ms Lawson but had then felt "sad and disappointed" that she had refused to speak to her after 14 years of working for the family.
Jurors previously heard that the defendants allege that Ms Lawson, who divorced Mr Saatchi earlier this year, regularly snorted cocaine and smoked cannabis during her 10-year marriage to the multi- millionaire.
But last week, Ms Lawson claimed she had only taken cocaine with her late husband John Diamond when he found out he had terminal cancer, and on another occasion in July 2010 during her troubled marriage to Mr Saatchi.
Giving evidence yesterday, Elisabetta said she regularly found signs that Ms Lawson was using cocaine, including a packet of white powder found in a toilet in the home she shared with Mr Diamond, as well as rolled-up banknotes and credit cards with white powder on them.
Asked if she had ever seen the food writer taking drugs, Elisabetta - who is also known as Lisa - said "No".
But she told jurors that she was aware that Ms Lawson had taken illegal substances.
She claimed to have found evidence of drug taking both at Ms Lawson's home in Shepherd's Bush, London, and later in the home she shared with Mr Saatchi.
Asked today by Ms Carpenter why she thought the substance she found in Ms Lawson's house was cocaine, Grillo told jurors: "I knew what it was. I watch TV. OK, I come from a little village but I'm not so naive."
Ms Carpenter questioned how - if the defendant did see cocaine in amongst Ms Lawson's possessions in her office - Mr Saatchi had not.
Grillo replied: "He was always upstairs in his bedroom. He'd never go in the office. Charles is a very sedentary person."
Grillo claimed that Mr Saatchi, Ms Lawson and members of her "Team Cupcake" had not told the truth during their evidence.
As she began her cross examination, Ms Carpenter asked: "Ms Grillo, is it your evidence that Ms Lawson has lied to the court?
"Yes," she replied.
"And Mr Saatchi?"
"And you're the one telling the truth?"
"And the other PAs, have they lied as well?" Ms Carpenter added.
"Yes," Elisabetta said.
She told the court that any money she had spent on the company credit loaned to her by Mr Saatchi had been authorised by the family.
The Grillos, of Kensington Gardens Square, Bayswater, west London, each deny a single count of committing fraud by using a company credit card for personal gain between January 1 2008 and December 31 last year.
The trial was adjourned to 10am on Monday.