WESTPORT — A speeding offense led to drug charges for a Fairfield man Friday morning, police said.

Westport police were conducting a speeding checkpoint on Wilton Road early morning Friday when they caught a vehicle traveling 52 mph in a 35 mph zone.

After pulling the vehicle over, police said they spotted a prescription pill container laying in plain sight.

A search revealed that the container had a plastic bag inside containing a brown powdery substance, in addition to a few loose pills, police said. Police later identified the powder as heroin. The pills, police added, did not match the label on the prescription bottle.

The driver of the car, 26-year-old Andrew Merritt, of Fairfield, was charged with two counts of possession of a controlled substance and failure to keep narcotics in their original container.

He was unable to post his bond, and he was transported to Norwalk Court to be arraigned later that morning.