Jenson Button, the British Formula One driver, may have been gassed during a burglary at a rented villa in St Tropez, a spokesman for the former world champion has been quoted as saying by UK media.
Button, 35, and wife Jessica were staying with friends in France when two men broke in and stole jewellery including Jessica's engagement ring, according to a report on the BBC.
The Sun newspaper reported that valuables worth 300,000 pounds ($465,150.00) were stolen.
"Two men broke into the property whilst they all slept and stole a number of items of jewellery including, most upsettingly, Jessica's engagement ring," the racing driver's spokesman told the BBC.
"The police have indicated that this has become a growing problem in the region with perpetrators going so far as to gas their proposed victims through the air conditioning units before breaking in."
|Button drives during the F1 Grand Prix in Budapest, Hungary last month [Getty Images]
Button, the 2009 world champion, has endured a nightmare year in Formula One.
His McLaren team have had their worst ever start to a season and scored just four points in eight races with a car that is way off the pace in the first year of their new partnership with Honda.
This season is Button's sixteenth.
The driver remains McLaren's most recent race winner, having triumphed for the under-performing former champions in Brazil at the end of 2012.