NEW YORK » A lawyer with the New York City detectives’ union says an undercover officer present at a motorcycle rally that turned bloody did not witness the attack on an SUV driver.

Attorney Phil Karasyk says the detective was off duty when he joined the Sept. 29 rally.

He rode up Manhattan’s West Side Highway after the SUV struck a biker. He followed the other bikers because he thought there had been a hit-and-run.

Karasyk says the detective later saw motorcyclists attacking the SUV. But he did not see the driver, Alexian Lien, pulled from the vehicle.

The detective did not come forward to disclose his presence at the scene for three days. Department officials are looking into the delay.