French police scramble to find missing toddler in remote Alpine village

French police searching for a 2-year-old boy, who went missing from his grandparents' garden in the French Alps on Saturday, said they had no clues as to what could have happened to him.

The boy, Emile, was last seen walking down the street of his grandparents' house - located in a remote mountain outpost with only two dozen inhabitants - by two witnesses on Saturday afternoon, a prosecutor said.

Police and gendarmes have entered every building of the settlement. Some 500 volunteers have also helped with the search, looking for Emile in the forests and fields that surround the village, the local prefect's office said on Twitter.

"At this point, we don't have any clues allowing us to follow any particular theory (on his whereabouts)", the local public prosecutor told franceinfo radio.

French authorities at the weekend opened a telephone hotline and released a photograph of the boy, a yellow flower tucked behind his ear.

BFM TV said authorities were using a recorded voice message by Emilie's mother, broadcast over loudspeakers from a helicopter, in the area of the search.

French media reported the boy went missing while his grandparents were preparing a car for a ride.