Mernda Sexual Offences and Child Abuse Investigation Team detectives have released CCTV footage as part of an ongoing investigation into a sexual assault near Lalor Railway Station earlier this year.
The incident occurred on Station Street about 12.10am on Thursday, 18 February.
A 32-year-old woman was crossing the road and entering Stockdale Park when she was approached from behind by an unknown man.
The man grabbed the woman and sexually assaulted her before throwing her mobile phone into bushes.
The woman screamed for help and the man got off her before fleeing on foot east along Station Street.
He then crossed over the railway tracks and continued into Vasey Avenue.
The woman managed to alert emergency services and was taken to hospital with injuries.
Prior to the incident, detectives believe the man caught a Mernda bound train from Flinders Street Railway Station about 11pm.
The man met with an associate on the train and both exited at Lalor Railway Station before walking towards Paschke Crescent about 11.45pm.
The offender returned to the railway station shortly after where he observed the woman crossing the road.
Following an extensive investigation, detectives have today released CCTV footage and images of a man who they believe can assist with their enquiries.
The man is perceived to be Asian in appearance, about 170cm tall, with a thin/athletic build, short black shaved hair and a black moustache.
He was wearing a white, green and black t-shirt with a black logo on the front, black pants and white runners with black stripes on the side.
He was carrying a black backpack with red lining.
Anyone who recognises the man or has information regarding the incident is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential crime report at www.crimestoppersvic.com.au