Mr Saatchi’s finance director Rahul Gajjar, 44, said he only began to suspect the sisters employed as assistants early last year.
During cross-examination by Karina Arden, representing Francesca Grillo, 35, Mr Gajjar said it was he who authorised the defendant’s credit limit, which started at £25,000.
Mr Gajjar said he increased it to £50,000 in Feb 2010 and then £100,000 in June 2011 as the defendant kept going over the limit and her card was frozen.
Ms Arden asked: “So the level of spending, which may be suggested by the Crown to be extraordinary — certainly you and Charles knew about it?”
“Yes,” Mr Gajjar replied.
Ms Arden went on: “He knew that a credit limit of £50,000 was insufficient at one point and therefore asked for it to be increased?”
“The details of the figure I don’t think Charles was aware of,” Mr Gajjar said.
Questioned about why Francesca and Elisabetta Grillo, 41, were expected to buy so much for the household, Mr Gajjar said: “Charles and Nigella didn’t generally go shopping like most people do. They would have their personal assistants shop for them.”
Ms Arden said Francesca worked long hours for the celebrity couple, often from 5am or 6am until late at night, and travelled around the world with them and their children.
Asked if Francesca “lived and breathed” Mr Saatchi and Ms Lawson, Mr Gajjar agreed.
Ms Arden said the sisters were treated differently to the other assistants, in that they were “like family”.
She said: “Francesca lived in the home. Her bedroom was actually very near to the bedroom of Charles and Nigella.”
Ms Arden suggested to Mr Gajjar that the sisters did not realise they were being accused of stealing when they were confronted by him, but rather that they were being asked what expenses had been personal such as taxi journeys they made on their own but while still carrying out their duties.
The court previously heard the defendants were open and apologetic about their spending at first, and it was only when they were sent a letter which they were asked to sign and admit they had stolen from the couple that they refused to co-operate.
Referring to Francesca, the barrister said: “That means, doesn’t it, that when she goes through the statement, that she was giving you an outline of what she had had a personal interest in. That’s right isn’t it? And you went though it very quickly?”
“Yes and yes,” Mr Gajjar said.
“What you end up with is a number of items which you put her name by... Without her being told that what is actually being alleged is that she has done something wrong?”
“That’s correct, yes,” Mr Gajjar said.
“The way you went about it, the process you used, was a bit like trying to trap her, wasn’t it?” Ms Arden asked.
“I don’t think that was the aim. It was always about trying to find a way out for the girls,” Mr Gajjar said.