Updated Thursday, March 24, 2011, at 9:51 a.m.

The Chicago Police Department says it’s investigating a video obtained by WBEZ that appears to show department officers allowing a young man to be taunted by a group of bystanders. Warning: The footage contains strong language.

The video was posted Saturday on YouTube by user King-Dubb. Both the footage and username have since disappeared from the video-sharing site.

In the video, two doors of a Chicago police vehicle are open. A young man in the backseat appears to be shielding his face from view as the onlookers shout insults and flash apparent gang signs to the camera. At one point, someone tells a camera operator, “Get a close-up.” At least two uniformed police officers are visible.

The circumstances surrounding the video are unclear but WBEZ criminal justice reporter Robert Wildeboer reports unconfirmed allegations over the years that Chicago police have intentionally dropped off youths in unfriendly gang territory.

Late Tuesday, the police department indicated it had received a complaint about the incident. “Department members reportedly demonstrated unbecoming conduct while an individual was in a Department vehicle,” the CPD said in a written statement to WBEZ. “The conduct that is alleged does not reflect the behavior and core values of the men and women of the Chicago Police Department nor our commitment to serve the community in a professional manner.”

The department said its Internal Affairs Division was aware of the allegations and an investigation had begun.

Clarification: This post has been updated to clarify that the identities of the individual voices on the video are unknown.