An alert citizen stopped an alleged impaired driver from getting behind the wheel, police say.

Perth OPP were called to the LCBO store in Mitchell last Saturday after a customer was refused service because the clerk believed he was intoxicated.

Upon arrival an officer was handed the keys of a GMC Sierra pickup truck from a citizen who said he took the keys from the man who had been refused service.

Police said they determined the man had been driving the truck. The man was arrested and taken to the Sebringville OPP detachment where he failed two breathalyzer tests.

A 53-year-old St. Marys man has been charged with driving while ability impaired and driving with more than 80 milligrams of alcohol in his blood.