Police have located a firearm believed to have been used in an armed robbery in Berwick on 17 March.
The hand gun was found in a parkland opposite Coral Drive and Manatoka Crescent, Hampton Park on 12 April.
The firearm was wrapped in green fabric inside a black satchel bag when it was found.
Detectives have released an image of the firearm and satchel bag in the hope that someone may recognise it and can provide further information.
The investigation is ongoing and anyone who may have witnessed the initial incident or with any information is urged to contact Crime Stoppers on 1800 333 000, or submit a confidential crime report at www.crimestoppersvic.com.au