Authorities on Tuesday were investigating another police officer accused of getting into a bar fight while off duty, the third such allegation to surface in this city in recent weeks.

The alleged incident was apparently videotaped, as were two other incidents involving off-duty police officers. The news comes a day after the head of the department announced his early retirement.

The department learned of the latest allegation last Wednesday, when an off-duty officer from Washington, D.C., filed a complaint against the Chicago officer, police spokeswoman Monique Bond said.

Bond declined to release the officer's name or talk about details of the video, which was first reported Tuesday by the Chicago Sun-Times.

Prosecutors have seen the video, but had not yet decided whether to file charges, said John Gorman, a spokesman for the attorney's office.

Bond said the state's attorney's office interviewed the Washington officer on Thursday and viewed the tape on Friday under a new policy designed to handle allegations of police misconduct more quickly.

Police Superintendent Philip J. Cline announced Monday his early retirement, but declined to speak about the two previous allegations.

One off-duty officer was accused of beating a female bartender in an attack caught on bar surveillance cameras and shown worldwide. He was charged with felony aggravated battery.

Six other officers were taken off the street after they were accused of beating four businessmen at another bar. The videotape of the alleged incident has not been shown publicly.