Detectives are investigating the attack on Formula One driver Jenson Button and his wife, who were holidaying at a rented villa on the French Riviera.
The attack is the latest in a series of robberies targeting high profile victims in southern France.
Other cases have seen the theft of millions of euro worth of jewels by criminal gangs.
:: March 2015 - Motorway Heist, Burgundy
Armed robbers attacked two heavily-guarded vans on a motorway near Auxerre, making off with €9m in jewels.
The guards were forced to abandon the vans before thieves drove off with the jewels.
Police later discovered the burned-out vans in a nearby forest.
:: July 2013 - Carlton Hotel, Cannes
A lone gunman entered the hotel in the luxury French resort and less than a minute later escaped on foot with jewels worth €125m.
The stash included pink and yellow diamonds, emeralds and sapphires.
The robbery was blamed on the 'Pink Panther' gang, who Interpol say have snatched jewels worth more than €397.9m since 1999.
The gang is thought to be a loosely-affiliated group of several hundred criminals from the former Yugoslavia.
:: May 2013 - Cannes Film Festival
Thieves make off with a €2.4m necklace during a celebrity party attended by the likes of Sharon Stone and Paris Hilton.
A week earlier, €938,021 worth of Chopard jewels had been stolen when a safe was ripped from a hotel wall.
:: May 2006 - Robbery Of Patrick Vieira
The footballer was targeted in a raid on his home near Cannes in 2006.
Vieira, his wife and daughter complained of feeling unwell after the robbery, and it was later confirmed gas was pumped into the air-conditioning system.
This kept the family asleep as the thieves stole jewellery from the premises.
:: May 2002 - Robbery Of Trinny Woodall And Susannah Constantine
The TV presenters were robbed when thieves broke into their room during the Cannes Film Festival.
The pair were rendered unconscious when thieves placed chloroform-soaked pads over their mouths as they slept.
A friend of Constantine told London's Evening Standard at the time: "They woke up one morning and their hands felt sticky, there was a funny smell in the room and they both felt hungover."
"Trinny doesn't drink at all and Susannah doesn't drink enough to make much of a difference. It transpired they had been chloroformed and all their jewellery had been stolen."