Jewellery stolen from the Louvre in Paris in a daring daylight robbery has been valued at 88 million euros (£76m; $102m), a French public prosecutor has said, citing the museum's curator.

Laure Beccuau told RTL radio the sum was 'extraordinary' but said the greater loss was to France's historical heritage. Crown jewels and pieces gifted by two Napoleons to their wives were among the items taken.

Thieves wielding power tools took less than eight minutes to make off with the loot shortly after the world's most-visited museum opened on Sunday morning.

With the thieves having not been caught more than two days on from the heist, experts fear the jewellery will already be long gone.

Ms Beccuau said she hoped announcing the estimated worth of the jewellery would make the robbers think twice and not destroy them. She added the thieves would not pocket the full windfall if they had 'the very bad idea of melting down these jewels'.

The items taken, previously described as having inestimable worth, include a diamond and emerald necklace Emperor Napoleon gave to his wife, a tiara worn by Empress Eugenie, the wife of Napoleon III, and several pieces previously owned by Queen Marie-Amelie.

Investigators found a damaged crown that used to belong to Empress Eugenie on the thieves' escape route - apparently having been dropped as they departed in haste.

Four masked thieves used a truck equipped with a mechanical lift to gain access to the Galerie d'Apollon via a balcony close to the River Seine. Two of them cut through a glass window using a battery-powered disc cutter and entered the museum, threatening the guards inside, who evacuated the building.

The thieves had tried to set fire to their vehicle outside but were prevented by the intervention of a member of museum staff. They were seen making off on scooters, leaving authorities to deal with the chaos of their escape.

French President Emmanuel Macron described the robbery as an attack on France's heritage and pledged that security measures would be reassessed. Security protocols had clearly failed, with an initial report revealing that one in three rooms in the Louvre lacked CCTV coverage and alarms did not activate during the heist.

Authorities are on high alert, believing they are dealing with a team of professionals given the operation's swift execution. Art recovery experts warn that investigators have just one or two days to track down the stolen items before they are likely lost for good, possibly smuggled out or dismantled for their precious metal and gems.

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