Louvre jewels are 'long gone' expert fears as critical robbery window passes

The chances of recovering the "priceless" valuables snatched from the Louvre are all-but over, an expert has warned.

Robbers stole the items of "immeasurable heritage value" from the world famous art gallery in Paris, France, in a lightning-quick heist that saw them gain entry and leave with the jewels inside just seven minutes on Sunday. Authorities are no closer to tracking down the thieves, who carried out the raid before escaping on motorbikes.

The brazen criminals were able to lift items that had once belonged to French royalty and colonial leaders after strolling into the iconic museum and smashing glass containers, using power tools. The theft was only allowed to happen due to a series of major security failings, and the incident caused a national outrage.

Thieves were able to gain access to one of the best-protected buildings in the world, and in the immediate aftermath an expert explained that if authorities don't locate the precious jewels within 48 hours, they will likely never be found. A team of 60 investigators continue working on the theory that an organised crime group was behind it - but one specialist fears it's now probably already too late.

Speaking hours after the heist, Chris Marinello, the chief executive of Art Recovery International, said it was always a race against time. He told the BBC on Sunday afternoon: "Police know that in the next 24 or 48 hours, if these thieves are not caught, those pieces are probably long gone. They may catch the criminals, but they won't recover the jewels."

Nathalie Goulet, a member of the French Senate's finance committee, called it a "very painful" episode for France, saying: "We are all disappointed and angry before adding that it was "difficult to understand how it happened so easily" - and confirming that the gallery's alarm had recently been broken.

She added: "I don't think we are facing amateurs. This is organised crime and they have absolutely no morals. They don't appreciate jewellery as a piece of history, only as a way to clean their dirty money." Meanwhile, French President Emmanuel Macron described the theft as an "attack on a heritage that we cherish because it is our history".

The only item recovered so far is an emerald-set imperial crown that once belonged to Napoleon III's wife, Empress Eugenie, which the masked gang dropped outside the museum as they fled. The crown, covered in more than 1,000 diamonds and said to be worth tens of millions, was found damaged.

In previous heists, the initial two days that follow the robbery - known as the 'golden hours' - have proved crucial in tracking down high-value artefacts, as the items are likely to remain a more limited geographic area and are therefore easier for authorities to contain. But after 48 hours, the items are more likely to have been broken up or melted down.

They may also be shipped internationally, meaning a far more complex cross-border operation is needed to trace them. It is feared that time is running out for the rest of the loot, which included: a sapphire diadem, a necklace and single earring from a matching set linked to 19th-century French queens Marie-Amelie and Hortense, an emerald necklace and earrings from the matching set of Napoleon Bonaparte's second wife Empress Marie-Louise, a reliquary brooch, 19th-century Empress Eugenie's diadem, and her large corsage-bow brooch.

Interior minister Laurent Nunez said the suspects entered from outside using a cherry picker via the riverfront facade to reach the hall with the 23-item royal collection. They targeted the gilded Apollon Gallery, where the Crown Diamonds are displayed, including the Regent, the Sancy and the Hortensia. The thieves smashed two display cases and fled on motorbikes in the "major robbery", Mr Nunez said, though no-one was hurt.