priceless

They were preparing a major upgrade that, finally, aimed to cover the vast museum’s exterior with cameras, bringing state-of-the-art security to an institution that houses many of the world’s most priceless works of art.

The Louvre is home to priceless works of art including Leonardo da Vinci's Mona Lisa.

Coming just days after thieves made off in broad daylight with eight pieces of priceless royal jewellery from the Louvre museum, organisers are at pains to reassure participants.

The burglars then used angle grinders to cut through a window and the display cases, purloining the priceless jewels in an operation that took less than seven minutes.

The charges come just days after thieves made off with priceless French crown jewels from the Louvre Museum in a separate daring raid.