FRENCH POLICE STEPPED up the hunt today for thieves who stole priceless royal jewels from the Louvre museum in Sunday’s daylight robbery.

As the museum remained closed for a second day yesterday, officials said 60 investigators were working on the theory that an organised crime group was behind the raid in which nine pieces of jewellery were taken.

A crown covered in more than 1,300 diamonds was dropped in the streets of Paris as the robbers fled.

Detectives scoured video camera footage from around the Louvre as well as of main highways out of Paris for signs of the four robbers who escaped on scooters on Sunday morning.

“There are a lot of videos and this is one of the investigators’ lines of work,” said Interior Minister Laurent Nunez.

But as disappointed tourists rebooked tickets to the world’s most visited museum, the heist – which lasted just seven minutes – also reignited a row over the lack of security in French museums, after two other institutions were hit last month.

Justice Minister Gerald Darmanin admitted to security flaws at the Louvre.

“What is certain is that we have failed, since people were able to park a furniture hoist in the middle of Paris, get people up it in several minutes to grab priceless jewels, giving France a terrible image,” he told France Inter radio.

Nunez has ordered better protection around cultural sites, his advisers said.

A report by France’s Court of Auditors seen by AFP covering 2019 to 2024 points to a “persistent” delay in security upgrades at the Louvre. Only a fourth of one wing was covered by video surveillance.

The thieves arrived at around 8.30am on Sunday, 30 minutes after the museum opened.

They parked a truck with an extendable ladder, like those used by movers, below the museum’s Apollo Gallery, clambering up and using cutting equipment to get through a window and open the display cases.

The world-famous institution, whose extensive collections include the Mona Lisa, may not open again until Wednesday, as it is usually shut on Tuesdays.

Queues of impatient visitors had snaked their way across the museum’s pyramid courtyard and under the tall arches of the main entrance gallery, hoping to get in Monday.

US tourist Jesslyn Ehlers, 38, and her husband rushed to rebook their tickets.

“We’re just kind of disappointed. We’ve been planning this for a very long time,” she said.

Carol Fuchs, another US tourist, had been standing in line for more than three-quarters of an hour.

“The audacity, coming through a window,” she told AFP. “Will they ever be found? I doubt it. I think it’s long gone,” she said.