Police have released the grandparents of a French toddler who went missing nearly two years ago for lack of evidence, but prosecutors said the family is not yet out of the frame in the mysterious case.

Philippe Vedovini, 59, and his wife, Anne, had been detained on Tuesday on suspicion of murder and concealment of a corpse.

Their grandson, Emile Soleil, went missing from their vacation home in a remote part of France between Aix-en-Provence and Aubagne in July 2023.

No trace of his body was found until the end of March last year, when a hiker in the mountainous area came across the skull and teeth of a child not far from their home.

But although there had not been sufficient evidence to bring any charges against the grandparents, Aix-en-Provence chief prosecutor Jean-Luc Blachon told a news conference that the line of investigation into Emile's family "is not closed".

Forensic evidence collected over recent months suggested that Emile had met a violent death, Blachon said, suggesting the involvement of a "third person in his disappearance and death".

Experts had notably established that Emile's body did not decompose in the items of his clothing that were found, and that an examination of his skull pointed to "violent facial trauma", Blachon said.

- Answers -

Emile's grandparents were questioned for 17 hours before being released, Philippe Vedovini's lawyer Isabelle Colombani said.

"The investigators did their job. We could see that a tremendous amount of work was done," she said, adding that her client had "answered all" police questions.

Julien Pinelli, his wife Anne's lawyer, said that his client had cooperated because she felt it was also her contribution to this investigation -- "the answers of which she is now awaiting".

Two of the Vedovinis' adult children were also detained and later released.

Philippe Vedovini and his wife are staunch Catholics and have 10 children, all of whom were home-schooled.

Emile was last seen walking alone on a street in Le Vernet, 1,200 metres (4,000 feet) up in the French Alps, in the late afternoon of July 8, 2023. He was wearing a yellow T-shirt, white shorts and tiny hiking shoes.

A massive search failed to find any sign of the boy until nine months later, when a hiker discovered his skull and teeth 1.7 kilometres (1.1 miles) from the village.

Police later found more bones and items of the boy's clothing.

The investigation over the past 21 months has involved 287 witness interviews, the examination of 27 vehicles and searches covering an area of 287 hectares (709 acres), Colonel Christoph Berthelin, in charge of the Marseille gendarmerie's search unit, told the news conference.

AFP