A witness chased and apprehended a 33-year-old parolee from NSW after a car collision on Hindmarsh Drive on Sunday afternoon.

A stolen black Mercedes Benz sedan collided with another vehicle at the intersection of Monaro Highway and Hindmarsh Drive in Symonston.

Police say the occupants of the other vehicle were taken to hospital with head and limb injuries, while the Mercedes driver fled on foot, with a witness chasing him over an extended distance across the Monaro Highway and through backyards.

The witness apprehended the driver in a backyard and police arrested him a short time later.

During the chase, the man allegedly dropped a backpack that police found to contain a trafficable amount of illicit drugs, a large amount of Australian currency, weapons including a machete and flick knife as well as paraphernalia consistent with drug trafficking.

The man is facing charges of driving a stolen motor vehicle, driving under the influence of a prescribed drug, negligent driving occasioning actual bodily harm, unlicensed driving, trafficking in controlled drugs, possession of proceeds of crime and other traffic offences.