EXCLUSIVE

Cee Lo Green is the target of an LAPD sexual battery investigation, TMZ has learned ... but the singer is adamant he did NOTHING wrong.

Law enforcement sources tell us ... a woman recently filed a police report with the LAPD, accusing "The Voice" judge -- real name Thomas DeCarlo Callaway -- of a sexual assault.

Our sources say detectives have already visited a restaurant in Downtown Los Angeles in connection with the case and questioned several employees, including the manager. We do not know if the alleged incident occurred at the restaurant.

The LAPD is mum on the identity of the alleged victim, when and where the incident allegedly occurred, and what Cee Lo allegedly did.

Cee Lo tells TMZ he categorically denies ANY wrongdoing. In fact, the singer says he hasn't been to the restaurant in question in 3 months ... and insists, "Nothing ever happened there or anywhere else."

We also spoke with a source who is constantly with Cee Lo ... who tells us, "I have never seen Cee Lo act in a physical way toward anybody."