A "chronic, structural underestimation of the risk of intrusions and theft" left the Louvre exposed for over 20 years to the kind of heist the museum experienced this month, French culture minister Rachida Dati says.

Security gaps contributed to a brazen daylight heist on October 19, in which four hooded thieves made off with eight precious pieces worth 88 million euros ($A155 million) from the museum's Apollo gallery, home to the French Crown Jewels.

A preliminary report into the theft found inadequate safety equipment, poor organisation and obsolete protocols at the museum, Dati told TF1 TV on Friday.

"The devices as they were installed, the alarm and security devices as they were installed on the day of the theft at the Louvre Museum, functioned properly," but that wasn't enough to p

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