A gang of armed thieves - some of them men dressed as women - swiped rings, necklaces and luxury watches at the Harry Winston store near the Champs-Elysees.
The Dec. 5 heist was one of France's biggest-ever jewelry robberies.
At least two of the bandits were men wearing wigs and women's clothes, a police official said.
The robbers also spoke a foreign language at times and appeared to know employees' names when they robbed the store at the height of Christmas shopping season.
Police on Monday spoke on condition of anonymity because police are not authorized to discuss cases publicly.
The brazen theft was among the world's costliest jewel heists.
The Harry Winston boutique was targeted in a similar theft in October 2007, when three people forced employees to open safes and hand over €10 million ($12.66 million) worth of jewels.
Five years ago, thieves plundered 123 maximum-security vaults in Antwerp, Belgium, stealing $100 million (€78.96 million) worth of diamonds in the biggest theft in the world's diamond-cutting capital.