London (CNN) -- A second former personal assistant to Nigella Lawson made drug use allegations against the celebrity chef Tuesday as she testified at her own fraud trial.
Francesca Grillo and her sister, Elisabetta, are accused of embezzling hundreds of thousands of pounds from Lawson and her ex-husband Charles Saatchi.
Francesca Grillo said she had not seen Lawson take drugs. But she told the Isleworth Crown Court in west London she had seen repeated evidence of drug use.
"At the beginning of 2012, there were a few episodes when she came down and she had white powder in her nostrils," she said of Lawson. "She brushed it off and said it was makeup."
Asked by her defense lawyer if that could have been the case, Francesca Grillo said it was "too white to be makeup."
Lawson told her that when she was working on a new book, she needed to stay up through the night, Grillo said.
The former personal assistant told the court that Lawson would have a runny nose for long periods of time, even in summer, and that she would have mood changes, going from very nice to "absent and grumpy."
She also described finding rolled-up bank notes with traces of powder in Lawson's handbag and seeing the remnants of cannabis use around the house.
Grillo said she spoke to Lawson's two children about her cannabis use. They told the former personal assistant that Lawson had trouble sleeping, so she would go downstairs and smoke with them because it helped her sleep.
Elisabetta Grillo, in her testimony last week, also told the court that she had seen indications of drug use by Lawson but had never seen her take drugs.
In her own testimony this month, Lawson confirmed she had taken cocaine half a dozen times, during two periods of her life, and used cannabis in the past. But she denied being a habitual user, saying, "I did not have a drug problem, I had a life problem."
Saatchi had said in an e-mail that Lawson had used drugs regularly, but in his testimony before the court last month, he backed off that claim.
In the e-mail, which the defense shared with the court at a pretrial hearing, Saatchi wrote that the two assistants would probably "get off" because Lawson was using cocaine and marijuana on a daily basis and "allowed the sisters to spend whatever they liked."
The two sisters are accused of spending large sums on luxury goods on company credit cards they were supposed to use for household expenses.
Both sisters deny the fraud charge.
Questioned by the prosecution about her spending Tuesday, Francesca Grillo insisted that Lawson had approved her purchases.
She admitted to having dresses, handbags and shoes from designers including Miu Miu, Christian Louboutin and Gucci.
The prosecution outlined the alleged top 50 unauthorized transactions by Grillo, including trips to New York and European cities such as Paris, Milan, Berlin and Antwerp, with significant purchases in exclusive stores.
In response, Grillo variously said that the trips were authorized by Lawson or that she couldn't remember the trip, who she went with or whether she was even on the trip herself. She suggested that other members of the family could have used her card.
Grillo said that Saatchi had shouted, banged his fists on a table and threatened to "destroy" her when he accused her of fraud this summer.
"You don't cross Charles Saatchi, everyone knows that," she said.
Grillo said it felt "like a personal vendetta" against her.
Elisabetta Grillo also said Lawson had authorized all her personal spending.