Fawkner Sexual Offences and Child Abuse Investigation Team detectives are hoping to identify a man following an up-skirting incident in Craigieburn last month.
The incident occurred at a Craigieburn Road shopping centre about 7.30pm on Wednesday, 22 July.
Investigators have been told a 20-year-old woman was inside a bathroom cubical when she noticed trade boots under the next cubical.
The woman then looked up and observed an unknown man filming her on his mobile phone from above.
The woman screamed and the man quickly fled before driving away in a dark-coloured 2002-2004 Holden Commodore VY.
Investigators have released CCTV and images of a man who they believe can assist with their enquiries.
The man is perceived to be Caucasian in appearance, aged in his 20s, and had short black hair and a beard.
Anyone who recognises the man or with information is urged to contact Crime Stoppers on 1800 333 000 or visit www.crimestoppersvic.com.au