It turns out that as early as 2018 the jewellery house of Van Cleef & Arpels conducted a security audit of the Louvre, in which it named as the most vulnerable spot precisely that balcony above the Galerie d'Apollon through which the thieves gained entry

It turns out that as early as 2018 the jewellery house of Van Cleef & Arpels conducted a security audit of the Louvre, in which it named as the most vulnerable spot precisely that balcony above the Galerie d'Apollon through which the thieves gained entry. The assessment noted at the time that the balcony could be reached via the goods lift, and that the surveillance cameras did not cover it fully.

The public prosecutor's office had not previously known of this report, and the investigation is now considering the possibility of a leak from within. According to the present director of the Louvre, Madame Laurence des Cars, the audit was not handed over when the leadership changed, and she saw it only after the robbery