Police from Prahran are investigating a theft which occurred in Prahran earlier this month.
Investigators have been told a man entered a bike store on Commercial Road about 8.45am on Wednesday 8 January.
Once inside the store the man examined a number of bikes before taking one off its mount and riding it out of the store.
Employees gave chase but were unable to catch the man.
The stolen bike was a GT Aggressor with a black and white frame and valued at $600.
The offender is perceived to be Caucasian, medium build and about 183 centimetres tall.
Investigators have released CCTV and images of a man they believe may be able to assist with their enquires.
Anyone who witnessed the incident or with information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report online at www.crimestoppersvic.com.au