A Dandenong man and a Notting Hill man have been arrested after police allegedly uncovered a modified shotgun and a 3D printer making a firearms part.
Police say they followed a stolen Subaru Impreza vehicle from a fast-food restaurant car park on the corner of Wellington and Dandenong roads Clayton about 12.15am on Friday, 18 July.
The vehicle had been allegedly stolen from the vicinity of Carrum Railway Station the day before.
Officers say they attempted to intercept the vehicle but it was immediately driven away at a fast rate of speed.
Police Air Wing followed the car to a home in Elwood Street, Notting Hill, where a man was observed dumping an item in a backyard shed, police say.
Officers entered the property and arrested two men.
A 3D printer, which was in the process of printing a firearms telescope, was located at the address, according to police.
Officers from the Dog Squad allegedly found a modified shotgun in the backyard.
A 39-year-old Notting Hill man and 30-year-old Dandenong man were expected to be interviewed that morning.
Investigations into the matter remain ongoing, police say.
Any information to Crime Stoppers on 1800 333 000 or crimestoppersvic.com.au