police officials abusing their power

Police, surprisingly higher officials of DSP and SSP rank are intentionally involving my friend in fake cases and lodging false FIR one after another without considering facts and proofs only because they have been bribed for doing so by my friend's enemy, who is an influential person. He is feeling helpless and is scared now that if he reports this to the highest authority, he may have to suffer more as he may also get bribed and getting a clean chit from judiciary would suck up decades and by then his life and career would be finished..Kindly advise how can he expose the corrupt practices being committed by rogues wearing khaki uniforms so that he gets out of the false cases he has been booked for. Now he has been called after a week at women cell for discussing and he knows that they will also trap him in a new case..Please advise as his enemy is a sound an influential person