The three -- one a member of the drug squad and the other two posted in the 19th district of Paris -- were arrested earlier this week. They could face charges.
Six people have already been charged over the July 2014 theft of cocaine worth 2 million euros ($2.2 million) from a secure room in the police headquarters overlooking the River Seine close to the Notre Dame Cathedral.
The chief suspect, identified as Jonathan G, is a former member of the drug squad who was seen by a police officer leaving the building with bags filled to the brim on the night of the theft.
He has been charged, together his wife and brother, who is also a policeman, and three other people. The 52 kilos (114 pounds) of missing cocaine has yet to be recovered.