An ambassador's son was sent to the Alps to overcome his drug addiction but returned to steal £10,000 from his parent's Kensington flat to fund his habit, a court heard.
Benjamin Fretwell, 50, has been battling a decade-long habit with the assistance of his mother, Lady Mary Fretwell, and father, the retired diplomat Sir John Emsley Fretwell.
The Alpine ski instructor was staying with his mother at his parents' £2.5m Kensington apartment when he stole the card.
Fretwell pleaded guilty to stealing the card in December last year and fraud by false representation by making cash withdrawals of £9,484.93.
Lady Fretwell OBE and her daughter attended Hammersmith magistrates' court to support Benjamin, but there was no sign of Sir John, the British ambassador to France between 1982 and 1987.
The court heard a statement from Lady Fretwell, who said she "phoned the police to get help for her son, not to see him prosecuted or sent to prison."
Last week Fretwell was given eight weeks' imprisonment, suspended for twelve months, and was ordered to complete 200 hours community service work.
Duncan Jones, defending, told the court that Fretwell usually spent the winter working in the Alps as a ski instructor and then went to France and Spain to look after his family’s houses.
“There, he doesn’t take drugs,” he said. “The problems are when he is here, in London under bad influences.
“He is clearly talented in his role of a ski instructor and that occupation keeps him clean for the majority of the year.”
Robert Simpson, prosecuting, said: "He was staying at her address for a period of time and his mother only realised her card had been used when she received her credit card statement."
Fretwell is six weeks into a two-month drug rehabilitation programme financed by his parents at the private Sanctuary Lodge in Halstead, Essex.
He is clearly talented in his role of a ski instructor and that occupation keeps him clean for the majority of the year
Duncan Jones, defending
"This was an opportunistic act by a man in the grip of an addiction to drugs," said Duncan Jones, defending. "He pleaded guilty at the first opportunity and realises he is in a precarious position today.
"He made a full admission to the police and for him it was a relief to be arrested and that put a stop to his offending.
"He is addicted to crack cocaine and heroin and has been for the last ten years and there was an overwhelming temptation when he saw his mother's bank card.
"His addiction consumed his thoughts and actions and he descended into a £300 a day drug addiction.
"It was his worst ever relapse and he could not control it while these cards, for those weeks, were usable.
"His intention is to sell his flat in Pimlico and use the proceeds to repay his mother."
Fretwell was also ordered to pay £85 costs and a £115 victim surcharge and told the court: "My mother will pay that and I'll pay her back."
Lady Fretwell, founder of the Passport for Pets pressure group, which campaigns for reformed quarantine laws, said from the public gallery: "It will come out of the flat cash, I've got a book."
Magistrate Robert Westlake told Fretwell: "This is a case aggravated by the amount involved.
"If you are convicted of an offence in the next twelve months it's highly likely you will go to prison these eight weeks.
"Your mother wants to help you and we are really pleased you are doing something to help yourself at Sanctuary Lodge.
"It's hanging over your head. That's why we are doing it and it will be disastrous for you if you are back."