Sources tell ABC 7 the veteran police officer works out of the 11th District on the city's West Side.
On Wednesday night, he allegedly received a sexual favor from a transgendered man in lockup. The officer allegedly promised the inmate to drop charges and let him go if the man committed a sex act on him. Sources also tell ABC 7 DNA evidence was found to confirm the allegations.
No charges have been filed yet.
A spokesperson with the police union says the Fraternal Order of Police will not be representing the officer because the alleged action was not duty-related. Instead, it was allegedly done on a personal level.
The officer is being represented by a private attorney.
The Chicago Police Department said in a statement: "The allegations are under investigation by the Bureau of Internal Affairs and the Cook County State's Attorney's office. The officer has been identified and has been relieved of police powers."
CPD is not releasing any details about the officer. It is unclear how long he has been on the force.