The owners of a timid dog may be wondering if the canine is their best friend after it led police to their drug stash.

Officers noticed the fierce-looking, but scared, mastiff cross in their car park on Friday.

When they approached the dog, it ran into traffic.

Concerned, the police followed the mutt down a laneway opposite the station.

The dog went to a unit in Hinderwell Street, where police say they found drugs and cash on a table.

An unlicensed shotgun and ammunition were allegedly found in a car on the premises and other drugs were found in the house.

A 31-year-old man from Queens Park will appear in Perth Magistrates Court on January 10 charged with possessing an unlicensed firearm and ammunition.

A 45-year-old Beverley woman is expected to be charged with possession of amphetamines and possession of a smoking implement.

A 32-year-old Scarborough man is expected to be charged with allowing the home to be used for drug taking and for possessing a prohibited drug.