French investigators have found and identified the "bones" of a toddler whose disappearance last summer in a tiny village in the French Alps shocked the nation, a prosecutor said Sunday.

Emile, two-and-a-half years old, was staying with his grandparents for the first day of the summer holidays when he vanished on July 8 last year.

Two neighbours last saw him in the late afternoon walking alone on a street in Le Vernet, at an altitude of  1,200 metres.

"On Saturday, the police was informed of the discovery of bones near the hamlet of Le Vernet," prosecutor Jean-Luc Blachon said.

Genetic testing allowed them "to conclude on Sunday that they were the bones of the child Emile," he added.

A massive on-the-ground search involving dozens of police officers and soldiers, sniffer dogs, a helicopter and drones failed to find the little boy in July.

Police on Thursday returned to the village, cordoning off the area and summoning 17 people including family members, neighbours and witnesses to re-enact the last moments before he went missing to try to solve the mystery.

Drones flew overhead in the drizzle to capture footage of the re-enactment.

Emile's mother and father, devout Catholics, were absent on the day of his disappearance.