A daring heist has left the art world in shock as a gang of thieves made off with invaluable jewelry from the iconic Louvre Museum in Paris. The brazen theft has French authorities scrambling for leads.

The Louvre, a must-see destination for millions of visitors each year, was sealed off on Sunday after the audacious daytime robbery, with soldiers deployed to secure the area.

French Interior Minister Laurent Nuñez shared on France Inter radio: “This morning, a significant robbery occurred in the Apollo Gallery. The perpetrators gained entry to the Louvre using an external freight elevator mounted on a truck.”

The Apollo Gallery is home to the French Crown Jewels and other priceless artifacts, including Louis XIV’s collection of hardstone vessels.

Just 250 meters away from the famous Mona Lisa, the theft was carried out in what Culture Minister Rachida Dati called a “professional four-minute operation.” The criminals fled on motorcycles with eight Napoleonic-era items, inadvertently leaving one behind.

The Louvre closed for the rest of Sunday as officials insisted the museum had undergone a major security upgrade in recent years, including new-generation cameras, perimeter detection, and a security control room overhaul. But critics say the measures come far too late.

The heist was denounced by French President Emmanuel Macron who pledged on social media to bring the criminals to justice.

“Everything is being done, everywhere, to achieve this, under the leadership of the Paris prosecutor’s office,” he posted on X.

Here is what you need to know about the robbery:

Around 9.30am on Sunday (6.30pm AEDT) several intruders forced a window, cut panes with a disc cutter and went straight for the glass display cases, officials said.

Nunez said the crew entered from outside using a basket lift via the riverfront facade to reach the hall with the 23-item royal collection.

Their target was the gilded Apollo 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, Nunez said.

No one was hurt. Alarms brought Louvre security guards to the room, forcing the intruders to bolt, but the theft was already done.

An attempt to set fire to the truck used to carry out the raid was foiled by a security officer, forcing the burglar to flee, officials said.

Eight objects were taken, according to officials: a sapphire diadem, necklace and single earring from a matching set linked to 19th-century French queens Marie-Amélie and Hortense; an emerald necklace and earrings from the matching set of Empress Marie-Louise, Napoleon Bonaparte’s second wife; a reliquary brooch; Empress Eugénie’s diadem; and her large corsage-bow brooch — a prized 19th-century imperial ensemble.

The thieves “lost or abandoned” an item – the crown of Empress Eugénie – wife of Napoleon III, during the daylight heist, prosecutors said.

The ornate gold piece, which features 1354 diamonds and 56 emeralds, was damaged.

How did the thieves complete the robbery?

Security experts say the gang planned the heist with military style precision.

British security consultant Will Geddes told Today this morning the robbers had done extremely thorough groundwork. 

”This was a very, very well planned operation … this particular group, highly organised, had no doubt done their reconnaissance beforehand … and came with appropriate equipment to get in and to get out with the substantial haul that they did.”

The gang probably timed the robbery with a change in the security detail at the Louvre, he said.

“I think there’s a very good chance there was probably a change of the security shift from the night team to the day team at this particular time,” said Geddes.

“So they may have been a little bit cold on the ground, i.e. they weren’t warmed up, they weren’t as vigilant as they might have been.”

The Louvre closed for the rest of Sunday for the forensic investigation to begin as police sealed gates, cleared courtyards and shut nearby streets along the River Seine in Paris.

An investigation for “aggravated theft by an organised gang and criminal conspiracy to commit a felony,” has been opened by Paris police under the authority of Paris public prosecutor’s office.

Video from the scene showed French police examining an abandoned furniture elevator positioned next to a corner of the Louvre, with its ladder leading up to a broken window off a balcony.

According to Le Parisien’s reporting, the police have found “two angle grinders, a blowtorch, gasoline, gloves, a walkie-talkie, a blanket and a crown” at the scene of the robbery.

A yellow vest used by the perpetrators to disguise themselves as workmen was found a bit further away, lost during their escape, the newspaper said.

What the gang behind the robbery intend to do with the stolen jewellery pieces is uncertain.

Geddes says selling the items without alerting authorities would be extremely risky, and they could have been “stolen to order”.

“There are certain individuals, certainly very wealthy individuals, particularly within organised crime, who may want to acquire these articles.”