Police said that several incidents of fake $50 and $100 notes have been used to buy goods in local businesses.
Several supermarkets, a take-away food shop and a taxi driver have been some of the victims of the crime since 15 June.
The counterfeit notes can be identified by looking at the translucent panel on the note, which have been cut out and the plastic stuck back on. Shopkeepers can also compare the note to one already in the cash register.
If you are handed note suspected to be fake, notify the police immediately by calling 000. Police will ask for a description of the person, a direction of travel and a description of any vehicles.
Anyone with information in relation to this is urged to contact Crime Stoppers on 1800 333 000.