Laurence des Cars is speaking for the first time since a gang of masked thieves - who remain at large - carried out Sunday's robbery.

Thieves used a stolen truck-mounted moving lift to scale the Louvre and steal royal jewels worth over $100 million in a lightning-fast Paris heist.

A specialized police unit is investigating a brazen daytime heist of eight pieces of jewelry worth about $102 million from Paris' Louvre Museum.

The only camera monitoring the exterior wall of the Louvre where they broke in was pointing away from the first-floor balcony that led to Gallery of Apollo housing the jewels, she said. "We failed these jewels," she said, adding that no-one was protected from "brutal criminals - not even the Louvre".

French authorities are under growing scrutiny about whether security failings allowed four thieves to steal royal jewelry worth over $100 million.

Laurence des Cars, the Louvre's president and director, is set to testify about the heist before the French Senate's Culture, Education and Sport Committee on Oct. 22.

Seven minutes is all it took for thieves to rob the world’s most famous museum Sunday. Here's a minute-by-minute breakdown of how it went down.

The Louvre in Paris reopened on Wednesday, three days after thieves made off with historic jewellery worth an estimated 88 million euros ($102 million) in a spectacular heist that has raised urgent questions over security lapses at the museum.