Police are appealing for help from the public after a man was assaulted in an unprovoked attack on a Hunter train.

The 21-year-old boarded the eastbound train at Metford Station at about 10am on Friday September 25 last year.

During the trip the man dropped a headphone on the floor and was attempting to pick it up when an unknown male passenger stood up and punched him in the head.

The offender is described as being of Aboriginal or Torres Strait Islander appearance, in his mid 20’s, with dark/reddish curly hair and a beard.

He was wearing a red, white and black hooded jumper, green camouflage cargo pants and white sneakers.

Anyone with information is urged to contact Crime Stoppers.

Police have released a CCTV image of the wanted man