Atlanta police say they've opened an investigation after video surfaced of a man's encounter with a plainclothes police officer on a downtown street.

The Atlanta Journal-Constitution reports that the officer is shown in the video using derogatory slurs that denigrate gays and blacks. The video was uploaded to social media on Jan. 26 by an Atlanta activist.

Atlanta Police Officer Lisa Bender said in a statement to The Associated Press on Wednesday that the man in the video is an Atlanta police officer. Bender says the department's Office of Professional Standards has opened an investigation into his conduct.