Le Parisien newspaper reported on Monday that the three central Paris restaurants have all been shuttered for between 45 days and four months while the investigation is carried out.
The newspaper named the three as Le Baci, in the fashionable Marais district, La Bocca in the rue de Montmartre and l'Escargot in the rue Montorgueil.
Investigators from the Paris drugs squad are believed to have found residues of cocaine in the restaurants concerned.
They were alerted to the alleged trafficking after arresting two dealers.
"These two suspects, aged 29 and 31, were found in possession of 60 grammes of cocaine as well as €2,500 ($3,220) and an automatic weapon," said a source close to the inquiry, quoted by the newspaper.
"Around 100 customers were being supplied by these two dealers and some of their accomplices. They were active every evening from 6pm until early morning in restaurants and bars in central Paris."
One of the restaurants concerned, Le Baci, is run by Thierry Costes, part of the famous empire which owns several fashionable restaurants in Paris.