Four-time Formula One champion Alain Prost suffered a head injury during a robbery at home, according to reports in Switzerland.
According to Swiss tabloid Blick, Prost and his family were the victims of a break-in by a masked gang that took place on Tuesday morning at their home in Nyon.
The report said that Prost's son was forced to open a safe in their home by the perpetrators.
A statement from the Vaud Cantonal Police said a major investigation has been launched, working in cooperation with French police and border security.
A statement said: "According to the first elements of the investigation, on Tuesday morning, May 19, several hooded individuals entered the house.
"Once inside, they threatened the occupants and slightly injured a family member in the head, in circumstances that remain to be established.
"The perpetrators then forced another family member to open a safe before fleeing with loot, the precise inventory of which is being evaluated."
As well as the Vaud police, a host of other agencies were involved, including regional Swiss and French police, science officers, customs investigators, and a psychological support team for the family.
Blick said the 71-year-old Prost was "visibly shaken by this brutal intrusion" and that he's left the home beside Lake Geneva.
The Frenchman, known as 'Le Professeur', won four F1 world championships in 1985, 1986, 1989 and 1993 during a 13-year career that included spells with McLaren, Renault, Ferrari and Williams as well as sharing a legendary rivalry with Brazilian driver Ayrton Senna.
