A tin of cash donations meant to go towards a memorial plaque for slain Bacchus Marsh woman Sarah Cafferkey has been stolen.
Police believed the tin was taken from the FoodWorks supermarket in Bacchus Marsh on Monday morning.
Officers were called to the supermarket about 2pm on Tuesday after the tin was noticed to be missing.
A police spokeswoman said CCTV footage suggested the thief stole it about 10.30am on Monday.
An image of the suspect has been posted on Facebook. He is of Caucasian appearance, and wearing a black hat, blue shirt and a white striped jumper.
Ms Cafferkey, 22, disappeared in November and her body was found days later discarded in a wheelie bin at a home in Point Cook. Police have charged a man with her murder.
Anyone with information should contact Crime Stoppers on 1800 333 000 or www.crimestoppers.com.au.