Chris Brown Could Be Prosecuted Over Exotic Monkey

Chris Brown got himself a pet monkey -- but never got a permit to keep her -- so now he's sans monkey and could face criminal charges ... TMZ has learned.

As we reported ... CB took heat last month after posting a pic of his 3-year-old daughter Royalty holding the baby capuchin monkey named Fiji, because people thought it was a danger to her and belongs in the wild. Chris told everyone to chill.

According to law enforcement ... several folks notified the California Dept. of Fish and Wildlife, who opened an investigation.

Turns out Chris never got a permit for the exotic pet, so authorities got a search warrant but before Chris' house got raided, he voluntarily agreed to surrender the animal.

According to our sources ... CB could be charged with having a restricted species without a permit, a misdemeanor, that carries a maximum of 6 months in jail. The case has been turned over to the L.A. City Attorney.

Chris' lawyer, Mark Geragos, tells TMZ, "As I leave my office in Downtown L.A. and walk past people sleeping on the street on my way to defend people charged by the City Attorney with selling medical marijuana ... now spending taxpayer money on investigating monkey business, this completes the circle on his absurdity."

As for Fiji ... she's fine.