Laurence des Cars told French lawmakers that the Louvre planned to double the number of CCTV cameras in and around the museum.
She admitted that the camera trained on the Gallery of Apollo, the south-side room where the jewels were kept, was facing the wrong way.
Paris city prosecutor Laure Beccuau told the Ouest France newspaper that up to 150 DNA samples and fingerprints had been retrieved so far as part of the police investigation.
The theft happened in less than eight minutes, after the thieves arrived at 09:30 on Sunday (07:30 GMT) after the Louvre opened its doors to the public.
They stole eight items including an emerald necklace and earrings given as a wedding gift by Napoleon Bonaparte to his second wife, Marie-Louise
As they fled, they dropped a 19th-Century diamond-studded crown belonging to Empress Eugenie.
Although it was recovered, the crown was damaged and des Cars said it had probably been crushed as the thieves prised it from its display case.
