Police allegedly located drugs, explosives, ammunition, and crossbows after executing a warrant in Lalor on Friday.
Police attended an address in Darebin Drive about 6.20am as part of an ongoing investigation.
A 53-year-old man, a 27-year-old man and a 45-year-old woman, all from Lalor, were arrested and officers searched the property.
During the search police allegedly seized, a loaded and privately manufactured firearm, two sticks of explosives, various cartridge ammunition, various 3D printed firearm parts, a quantity of cannabis, a privately manufactured taser, mobile phones, weapons including knives and crossbows.
The woman was issued with a cannabis caution and the two men were released pending further inquiries.
The investigation remains ongoing.
Anyone with information can contact Crime Stoppers on 1800 333 000 or www.crimestoppersvic.com.au.
