A four-year-old British girl spent eight hours hiding among the bodies of three adults, thought to be her mother, father and grandmother, who were shot dead in a car in the French Alps.

The child, apparently on a family camping holiday from Britain, was found by police unhurt shortly before midnight on Wednesday huddled on the floor behind the front seats of the car under the legs and skirt of one of the dead women.

A second girl of about eight, thought to be her sister, had been found earlier with serious injuries having been shot in the shoulder and severely beaten on the head.

A French cyclist was also found shot dead at the scene on a mountain road near the village of Chevaline, close to the Annecy Lake and the Swiss border.

The man, a young father who lived in the area named Sylvain Mollier, "just happened to be riding by" at the time of the attack, officials said.

"I do not call this the work of professionals. I call it an act of enormous savagery," public prosecutor Eric Maillaud told a news conference in the town of Annecy, southeastern France.

Police had no idea of the motive, he said.

The owner of the UK-registered car, who was found dead at the wheel, was Iraqi-born Briton Saad al-Hilli from Surrey, southern England, a source close to the investigation told the Reuters news agency. 

Source: Reuters