Melbourne Embona Taskforce detectives are hoping to identify a man following an alleged assault and attempted robbery in Melbourne's CBD on 3 November.
Police have been told a man was approached by a group of men on Swanston Street near Little Bourke Street about 4.20am.
It is alleged the offenders attempted to rob the 24-year-old man before assaulting him and hitting him to the head with a bottle.
The Reservoir man was taken to hospital with head injuries.
Investigators have released an image of a man that may be able to assist with their enquiries.
The offender is perceived to be Pacific Islander in appearance and was wearing a black cap, dark clothing and white runners.
Four men have been arrested and charged in relation to the assault and the investigation remains ongoing.
Anyone with information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential crime report at www.crimestoppersvic.com.au
