Port Moody Police say faulty breathalyzers were used in 2011.
On its website the police department says the results of a independent investigation have determined faulty breathalyzers were used in 14 out of 174 roadside tests administered that year.
The police department requested the investigation out of concern some of the roadside screening devices were improperly calibrated.
The results of the investigation have now been forwarded to the Office of the Superintendent of Motor Vehicles.