A diamond necklace worth close to 2 million euros (2.6 million dollars) has been stolen on the sidelines of the Cannes Film Festival, the second such jewellery theft at the event in a week, French radio reported.

The necklace from Swiss jeweller De Grisogono was stolen during a gala event organized by the company at a luxury hotel in Cap d'Antibes, about 13 kilometres from Cannes, France Info radio said, quoting the jeweller.

Several celebrities, including US socialite Paris Hilton, had attended the event.

Police were investigating the theft. The necklace, which was reportedly under the protection of a private security company, is said to be valued at 1,924,000 euros.

De Grisogono was not immediately available for comment.

Last week, a case of jewellery worth around 1.4 million dollars belonging to Chopard jewellery designer was snatched from a hotel in the centre of Cannes.

Police are still searching for the burglars.