DIRTY COP: First video of NYPD undercover cop going rogue at brutal biker road rage attack’

The first video that appears to show an undercover cop charged for taking part in the brutal gang bike attack on a family in their SUV, can be revealed today.

It comes amid claims that he may have ‘gone rogue’ after spending too long undercover, according to a report.

Detective Wojciech Braszczok may have become so immersed in his cover story that he forgot himself when he allegedly took part in the assault, suggested a DNAinfo source.

In an echo of films like Donnie Brasco – in which an undercover cop feels the strain of his double life – Braszczok may have stepped over the line.

A source said: ‘Sometimes an undercover spends too much time in a role, becomes the character and forgets what side of the law he is on’.

A YouTube video of the day of the attack shows a rider fitting Braszczok’s description in the main group chasing Alexian Lien’s Range Rover.

The video shows Braszczok apparently at the front of the group chasing Lien at all times. At no point does he try to stop the pursuit.

At around two minutes he surges from the back and positions himself to the left of the vehicle.

His red bike – what looks like same one as in his online postings – is later seen right behind the SUV boxing it in.

When Lien stops for the first time Braszczok has moved to its driver’s side and as one biker tries to open the driver’s door, Braszczok goes to get off his bike to assist, but Lien speeds off.

Then he is seen again at the end when Lien is set upon during the second, final confrontation.

The video shows Braszczok apparently pulling up alongside the right of the Range Rover.