Lloyd's of London has offered up to one million euro (£864,000) for information leading to the recovery of jewels stolen from a Cannes hotel.
An armed man pulled off a brazen daylight heist at the luxury Carlton Hotel on July 28, in one of the world's biggest ever jewellery thefts.
The jewels, which were taken from the hotel used to film To Catch a Thief - the 1955 film directed by Alfred Hitchcock about a jewel thief, had an estimated value of £88.48m.
Carrying a semi-automatic pistol, his head covered with a cloth, the robber stole jewels that were part of an exhibition by a group owned by Israeli billionaire Lev Leviev.
Authorities say the man escaped with "all kinds of different" jewellery, including "rings, pendants, and earrings encrusted with diamonds".
The exhibition was held in a wing of the hotel with direct access to the street and police said they had not been told that it was taking place.
Prosecutors say the robber entered the exhibition room through a French window that opened on to a terrace, which itself looks on to the popular Croisette avenue in Cannes.
"A reward of up to €1m pro rata is offered to the first person who provides information which leads to recovery of the goods. Offer subject to certain conditions," Lloyd's said in a statement.
Cannes has fallen prey to thieves several times recently, notably during this year's film festival, which attracts a glittering array of celebrities from the movie world.
In a pre-dawn heist at a hotel during the festival in May, thieves stole £660,000 of jewellery due to be loaned to movie stars.
That robbery took place in the hotel room of an American employee of Swiss jeweller Chopard while she was out for the evening, police said.
Anyone with information about the jewel heist should contact SW Associates at reward1millionE@gmail.com.