The theft took place in the chic 8th district of the French capital, at a storage facility for luxury watchmaker Richard Mille.
One of the police sources said the safes had not been attached to anything.
Local residents alerted police after noticing strange comings and goings in the area on Sunday night.
The wealthier districts of Paris are home to some of the world's top brands, making them a prime target for robbers and thieves.
In May robbers with pump-action shotguns raided a Chanel boutique, a month after criminals rammed the storefront of another Chanel store with a 4x4 car, making off with several expensive handbags.