A 26-year-old man was charged overnight after police allegedly caught him in possession of a gun in Midvale.

Police will allege a Holden Maloo stopped on Great Eastern Highway about 11:30pm and the occupants threw a bag over the back fence of a property.

The bag allegedly contained a sawn-off bolt action rifle with a round in the chamber, as well as two replica pistols, a baton, handcuffs, and a balaclava.

A Bellevue man will appear in court on June 7 to face charges of possessing an unlicensed firearm and ammunition.

A 27-year-old man was also arrested and will appear in court on a later date.