A homemade weapon, constructed from plastic and other “readily available materials”, was allegedly seized by police in Bayswater this month.

It marks the first time a fully functional 3D firearm has been seized in WA.

Detectives from the drug and firearm squad will allege they found the gun after executing a search warrant at a home on Slade Street, occupied by an 18-year-old man.

Along with the semi-automatic - which is capable of firing 9mm rounds and has the same caliber as police weapons - police also allegedly found five gel blasters, a silencer, ammunition and a barrel manufacturing station.

Sunrise correspondent Matt Tinney has the details.