The Cannes Film Festival has been hit with another jewellery heist drama after a $2.5 million (£1.6 million) diamond necklace disappeared during a star-studded party. Fawaz Gruosi, the founder of Swiss gem firm De Grisogono, has revealed the sparkling item was part of a collection which was being paraded by models around a glitzy Hotel Du Cap-Eden-Roc bash in Antibes, attended by Sharon Stone and Paris Hilton, on Tuesday night (21May13). But when he took stock of the jewellery at the end of the party he realised the necklace was missing. He tells Reuters, "We don't know exactly what happened... It was one of the most beautiful items we had. The police are trying to figure out what happened." The latest theft comes less than a week after Chopard gems worth an estimated $1.4 million (£900,000) were stolen from a hotel suite.