The 22-year-old was stopped in his vehicle for a random breath test in Queanbeyan about 1.40am on Saturday when officers became suspicious of his behaviour and began searching the vehicle.

The man allegedly resisted and bit a police officer on the arm.

He was tasered and arrested.

A firearm, believed to be a pen gun, ammunition, cash and two bags of illicit drugs were found in the driver's pants, police say.

He faces a string of charges including assaulting police.

The man is due to face Queanbeyan Local Court on Sunday.