Six cops were at the rally where motorcyclist beat SUV driver View Full Caption

MANHATTAN — The NYPD Internal Affairs Bureau is looking into the role of half a dozen off-duty cops who were among the motorcyclists who pulled a man from his SUV and beat him after a high-speed chase up the Henry Hudson Parkway on Sunday, sources said.

There was even an off-duty undercover narcotics officer who watched as bikers pulled the driver, Alexian Lien, 33, from his Range Rover in front of his terrified family and beat him, the sources said.

Internal affairs has the names of two detectives, one sergeant and three police officers who were either on the highway when motorcyclists confronted Lien, who was driving with his wife and 2-year-old daughter, or witnessed the assault at West 178th Street, according to sources.

Bikers Clash With SUV Driver View Full Caption YouTube/Daphne Avalon

One of the detectives was arrested earlier in the year for assaulting his girlfriend, who is an assistant district attorney in Queens, according to sources.

Authorities are also looking into the actions of a group of city corrections officers who were also near the attack, the sources said.

The cops will likely face disciplinary measures because they did not immediately come forward and tell their supervisors they attended the rally, according to the sources.

An NYPD spokesman confirmed the investigation but declined to comment further.