Police have released CCTV footage as part of their investigation into a sexual assault in Broadmeadows last year.
The footage shows a male walking east along Nicholas Street then turning left onto Gosford Street in Broadmeadows shortly before the attack.
Detectives made a public appeal for assistance in relation to the incident last December.
Investigators have been told a 37-year-old woman was walking along a track between Seabrook Reserve and Railway Crescent when she crossed paths with an unknown male about 7.55pm on Friday, December 11.
The woman continued to walk west for a short distance before the male approached and grabbed her from behind.
He sexually assaulted the woman before she was able to free herself. The man then fled the scene towards the railway line.
The male is believed to be a youth or in his late teens, Caucasian in appearance, about 178cm in height, with a muscular build and broad shoulders.
At the time of the incident he was wearing a grey hooded jumper and black shoes.
Detectives are keen to speak to anyone who may be able to assist identifying the male, or who was in the area at the time of the incident and witnessed a male matching the description.
Anyone with information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report online at www.crimestoppersvic.com.au.