Police launch murder investigation after bones belonging to at least four people are discovered on sea bed near Antibes

This article is more than 6 years old

This article is more than 6 years old

The macabre discovery of human bones on the sea bed off the French Riviera, near the millionaires' playground of Antibes, has baffled investigators and prompted a murder inquiry.

The remains, which appear to come from at least four individuals, include a skull on which detectives discovered the faded inscription "death to paedophiles".

Investigators say the remains, discovered by a diver six metres beneath the surface near the foot of a rock cliff at Cap d'Antibes, south-west of Nice, have been in the water for at least a decade.

DNA tests on one of the other bones, a humerus, have revealed the detached upper arm belonged to a 17-year-old Parisien, Stéphane Hirson, who disappeared in 1994.

The remains – a femur, or thigh bone, from a male; one male and one female humerus; a skull and a part of a jaw – were first spotted by a diver looking for sea urchins in February this year.

Specialist police divers then brought them to the surface for examination and tests. Scientists have struggled to obtain genetic material from the bones but say the sections of limb belong to bodies under the age of 30 and the skull from a man under 50.

"We are confronted with a series of enigmas," Georges Gutierrez, the public prosecutor at Grasse, told French journalists on Wednesday as he announced the opening of the inquiry into cases of murder, kidnapping, imprisoning and taking and receiving corpses.

"There are a thousand questions in this case. Why, for example, a single bone for each individual and not other parts of their skeleton?"

Hirson was reported missing in February 1994, days before his 18th birthday. He had been released from a brief stay in a psychiatric hospital and was due to meet a friend when he disappeared without trace.

A family member told French radio the missing youth had "no reason to be in the Côte d'Azur when he had told his mother he was planning to go to Spain".

"The family has no connections in the south-east" of France, she said.

An unnamed source close to the inquiry told Le Parisien newspaper that the skull was also marked with what looked like a shooting target.

"It was in dark ink, but identifying what kind of ink or the handwriting is complicated," said one police officer. "The bones were in a good, well-preserved state and very white."

Gutierrez said tests on the remains were ongoing. "We're hoping the experts will be able to tell us how long they have been in the water," he said.