Nice (France), Aug 7 (IANS): Burglars may have used anaesthetic gas to rob Formula One driver Jenson Button and his wife Jessica at their rented villa here, a spokesman said on Friday.

Valuables worth 300,000 pounds were reportedly stolen. The couple had married in December.

It is believed that the two men who stole jewellery, including Jessica’s engagement ring, knocked out the couple with gas pumped in through air conditioning vents during Monday’s break-in, bbc.com reported.

The former F1 champion's spokesperson said the couple was unharmed but everyone was "unsurprisingly shaken".

"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 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."

The 35-year-old Button, who drives for McLaren, is based in Monaco, about 130 km from Saint-Tropez.