High class Swiss jewellers De Grisogono announced on Thursday that a diamond necklace believed to be worth around €2 million was stolen from the Hotel Eden-Roc in the resort of Antibes, according to reports in the French media.

"A necklace was stolen during the Cannes festival and we are working with the authorities," a De Grisogono spokesman said, refusing to comment on the circumstances of the theft or exact value of the necklace.

Police said they were investigating a complaint filed by De Grisogono and that the necklace had gone missing in the resort town of Antibes near Cannes.

France Info radio reported that the missing diamond necklace was worth 1.9 million euros and had been stolen during a gala evening Tuesday at the chic Eden Roc hotel attended by, among others, Paris Hilton and Sharon Stone.

It is second high value theft to hit the Cannes festival in a matter of days.

On Friday thieves stole Chopard jewellery worth up to €1 million from a safe in a room at the Novotel hotel.

In a scenario itself worthy of a movie, thieves entered the hotel room of an American woman employee of Swiss bijoutier Chopard and ripped out the strongbox in the wardrobe, according to police reports.

A Chinese film producer blasted France for its “really bad” level of public safety after he was the victim of a burglary at this year's festival.

Zhang Qiang expressed his outrage on his blog just days after the apartment he was renting in the resort was targeted by thieves.

The vice president of the powerful state conglomerate China Film Company discovered the apartment he had hired out for the festival had been targeted when he returned home from dinner last Thursday.