Formula One world champion Jenson Button claimed that he had also been sedated after more than £300,000 worth of jewellery was taken from his rented villa in Saint Tropez 2010.Experts have doubted the claims, saying gasses such as ethers and chloroforms would cause coughing and spluttering to anyone exposed to high doses. It would not be possible to pump high enough concentrations of alternative gasses, such as nitrous oxide, through an entire villa to knock victims out for long enough, some experts have said. “I’m pretty convinced we must have been gassed or something, because they were in all of the bedrooms – they went where they wanted, into each room, opening and closing the drawers, searching through handbags etc,” she told the Sunday Express.“You have got to have some kind of confidence to do that and to be quite satisfied that people aren’t going to wake up.”Ex-Arsenal star Patrick Vieira was targeted while holidaying in Cannes in 2006. Gas was discovered in the ventilation system after the French midfielder woke feeling unwell to discover his home had been raided with jewellery and his Mercedes 4×4 missing. I’m pretty convinced we must have been gassed or somethingMindy Hammond But describing their break-in last month as a “horror story” Mrs Hammond said before going to bed she had heard male voices behind the living room door but assumed it was some of their guests.She only realised the next morning she had, in fact, had a close shave with the thieves. The neighbouring house had also been robbed that night. she said, and after the incident family employed a security guard. Police arrested the two burglars within 48 hours as they were caught on CCTV. British Formula One world champion Jenson Button claimed he was gassed after £300,000 worth of jewellery was stolen from his villa in Saint TropezCredit:Mark Thompson/Getty Images Sport Fears are emerging that Saint Tropez’s knockout gas burglars have returned after Richard Hammond’s family were robbed in their sleep.Thieves are known to have previously pumped anaesthetic gas through air conditioning systems in a series of raids on luxury villas on the French Riviera.Mr Hammond’s wife, Mindy, said she is “convinced” the family were targeted while staying at an up-market property on the French coast. The former Top Gear star’s teenage daughter, Willow, had a watch stolen from her bedside table while she slept and the couple had cash stolen from their wallets. Mrs Hammond said she was not even woken by her husband Richard’s snoring but when she did eventually stir she noticed all the bedroom doors were open. Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.