Nice - Jenson Button may have been gassed during a burglary at a rented villa in St Tropez, a spokesperson for the former Formula One world champion was quoted as saying by British media.
Button and wife Jessica were staying with friends in France when two men broke in. They stole jewellery worth €300 000, according to a police spokesperson for the Var region.
"Mr Button learned about the burglary as he woke up. Nobody was hurt," the police spokesperson said.
A spokesperson for the racing driver told the BBC that Jessica's engagement ring was among the items stolen and that gas may have been used in the burglary.
"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," he said.
Button, the 2009 world champion, has endured a nightmare year in Formula One.
His McLaren team had their worst ever start to a season and had scored just four points from their first eight races before Button and team-mate Fernando Alonso picked up 13 points between them at the British and Hungarian Grands Prix.