Police in Cannes, France, are still investigating one of Europe's largest jewel heists in recent years. 

It happened in broad daylight yesterday afternoon, when a lone gunman walked into the famous Carlton Hotel, threatened staff and tipped €40 million worth of jewels and watches into a briefcase. 

Detectives believe he may have had an accomplice waiting outside to aid his getaway. 

Raid "could not have been more audacious"

Speaking to the Nice Matin newspaper, a police source said: “The raid took place in broad daylight when there were hundreds of holidaymakers enjoying the sunshine. It could not have been more audacious.

“The thief took advantage of the crowds and the relaxed Sunday atmosphere – he could easily have had others working with him.”

Spate of recent jewel heists in Cannes

It's the third major jewel heist at the French Riviera resort in recent months, prompting many to speculate at possible links between the raids. 

The first targetted the world-famous Cannes Film Festival, where thieves made-off with €1 million worth of diamonds.

A week later a diamond necklace worth €1.8 million disappeared during a party attended by Hollywood stars at the Hotel Du Cap-Eden-Roc.

Police have made little progress in either investigation and no arrests have been made.