Moorabool Crime Investigation Unit detectives are investigating following the theft from a car and subsequent deceptions at the weekend.
Investigators have been told a black Mazda 3 hatch was broken into at Peppertree Park in Grant Street, Bacchus Marsh on Sunday, 18 October.
A bank card from the theft was used at various stores in the Bacchus Marsh area the same day.
Police have released images of a man they believe can assist with their investigation.
The man is perceived be Caucasian in appearance, aged in his 20s or 30s, and is of average height and build.
Anyone with information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report online at www.crimestoppervic.com.au.