Cops working the Jussie Smollett case allegedly had seriously loose lips, and now the police force is launching an internal investigation.
Chicago PD tells us its Chief of Detectives opened the investigation out of concerns the force was leaking like a sieve. CPD adds there's been a ton of "inaccurate" info in the media, and they want to know who's putting it out there.
A police spokesman tells TMZ ... "When there are allegations of information being leaked, an internal investigation has been opened and we are also looking at our vulnerabilities."
Worth noting ... the Smollett case also caused upheaval at the hospital where he was treated after the alleged attack. Dozens of staffers were reportedly fired for looking at his records without authorization.