French police have launched a probe after British Formula One driver Jenson Button and his wife Jessica Michibata were burgled on the French Riviera, but authorities cast doubt on suspicions that sleeping gas was used in the robbery.
The couple were in a rented villa in Saint-Tropez with friends when thieves made off with Jessica's engagement ring and other valuables worth €426,000 on Monday evening, a source close to the probe said.
"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," said a spokesman for Button, the 2009 world champion.
The thieves may have operated by pumping sleeping gas into the house through the air conditioning, he added.
"Whilst unharmed, everyone involved is unsurprisingly shaken by the events."
However, authorities cast doubt on the idea that gas was used.
"As far as we know, there has never been any robbery in the Saint-Tropez region where gas was used to put victims to sleep," said Philippe Guemas, a local prosecutor.
"Jenson Button's entourage made this unfounded assertion because the driver didn't feel well the next day.
"We took blood samples, which will be analysed."
Button, 35, is currently signed to team McLaren and lives in Monaco, along the Mediterranean coast from Saint-Tropez.
He married Ms Michibata, an Argentinian-Japanese fashion model, in Hawaii in December.
Subject: Doubt cast on claims F1 driver Button gassed in burglary 
