Specialist police wearing shields and body armour have spent almost six hours at a home in Corio, with a man suspected of having a firearm holed up inside.
Police negotiators swung into action after a caller to the 000 (triple-zero) emergency line claimed an armed man had barricaded himself inside.
Neighbours were told to remain indoors as police from the Critical Incident Response Team (CIRT) surrounded the property and sealed off nearby streets.
Officers using loud-hailers eventually made contact but the man refused to the building.
More than three hours after the drama began, a woman emerged safely from the house but the man remained inside.
At one stage tear gas was deployed in an unsuccesful effort to convince the man to come out.
The incident was resolved peacefully just after 5pm when a man was led away in handcuffs.
The 24-year-old, from Newcomb, was treated by paramedics at the scene for the effects of tear gas before being taken to hospital for assessment.
Police said there was no suggestion that a firearm was involved.
No charges have yet been laid.
