Button was staying with friends in a Saint Tropez mansion when they woke to find personal articles worth over $450,000 had been stolen. They believe gas was used in the burglary, as they woke feeling unusually groggy.

But local Police have since played down the claims, and are waiting for the results of medical tests to establish if a gassing did occur.

“To our knowledge there has never been a burglary like this in St Tropez where gas was used to knock out the victims,” Philippe Guemas, deputy prosecutor in Draguignan, told Europe1 Radio.

“Nothing has been established. Jenson Button’s entourage has made this claim as the driver didn’t feel well the following day.

“We have taken blood samples, which will be analysed.”

Gas gangs: truth or myth?

Last year, the UK’s Royal College of Anaesthetists went on record stating that the so-called gas gangs were a “myth”.

This is despite many claims to the contrary from high-profile theft victims like French footballer Patrick Vieira, fashionistas Trinny Woodall and Susannah Constantine, plus a number of villa owners, motorhome users and commercial truck drivers local to the region.

Dr Liam Brennan, vice president of the Royal College of Anaesthetists, told Sky News: “We find it very difficult to understand how anaesthetic agents could be delivered in the concentrations required to produce that sort of effect.

“Nitrous oxide is an anaesthetic agent that we use, but it is a very weak agent and the concentrations required to render somebody unconscious are extremely high.

“It would simply not be possible to pump enough into to the environment of a house.”

However, Professor Michael Levi, an expert in security and organised crime at the University of Cardiff, believes the volume of cases over the past decade suggests otherwise.

He told The Telegraph newspaper: "In this case it may be that you have a gang of relatively low-level criminals working with or being supplied by a chemist who has expertise on how to administer the gas without harming anyone.

"There is obviously a risk in that if you don't administer the dosage correctly you could kill someone, or they could wake up in the middle of what you are doing.”