A video surfaced Thursday showing an undercover New York City police officer kicking a fellow officer in the head, apparently mistaking him for a suspect.

The news website DNAinfo New York published the video of a January confrontation that started with two transit cops and a man who allegedly tried to skip a fare at a subway station in Coney Island.

The suspect appeared in to physically struggle as they tackled him to the ground and attempted to cuff his hands.

Almost immediately, several uniformed officers streamed from the subway entrance, with what DNAinfo described as an undercover cop tagging along.

The plainclothes officer appeared to mistake one of his fellow officers on the floor for the suspect and kicked him in the head. A loud thump is heard on the tape.

“He kicked the cop,” a nearby bystander could be heard saying on the video.

The officer appeared to have realized his mistake soon after. He rubbed the head of his colleague and then grabbed hold of the suspect and punched him.

The cop is being investigated by NYPD’s Internal Affairs Bureau and the Brooklyn District Attorney, DNAinfo reported. He was ordered to turn in his badge and gun after the clip appeared, officials told the news site.

The incident was filmed by a professional photographer, who originally posted it on Google+ before it was taken down and subsequently obtained by DNAInfo.

Watch the video below, courtesy of DNAinfo: