CCTV of bashed Vic cop found

New security camera images have emerged in the case of a policeman who was king hit outside a Melbourne nightclub in 2013.

The officer was responding to a fight outside the club, in Hawthorn, in the early hours of October 27 when he was punched in the head from behind.

He required hospital treatment for concussion and whiplash.

"This was a savage, unprovoked and cowardly punch on a member who was just going about his job," according to a Victoria Police statement.

Police have received new information, and have released security camera vision of a man they want to speak to over the attack.