A 36-year-old Chapman man, the subject of a Good Behaviour Order, has been arrested after a gun and knife were found in his possession while being treated for minor injuries in a Canberra hospital on Tuesday morning.

Police went to the the Canberra Hospital and seized a black pistol and a knife. Police also also say they found four combination lock boxes, digital scales and a number of small plastic ziplock bags.

On accessing the lock boxes, they found cash, a crystal substance believed to be methamphetamine and drug paraphernalia.

The man was arrested and faces charges of unauthorised possession of a prohibited firearm, possessing a knife without a reasonable excuse and possessing drug of dependence.