Calgary police are looking for a man who pretended to be an officer while making a traffic stop.

A man driving along Stoney Trail near Country Hills Boulevard N.E. at 9:30 p.m. on Wednesday was pulled over by what appeared to be an unmarked police vehicle. The white Ford Crown Victoria had flashing red and blue lights in the rear window and grill.

"[A man] then got out of his car and approached the victim, claiming he was a police officer, and asked for his driver's licence and registration. The victim was suspicious, and asked the man for his police identification. He refused," police wrote in a news release.

The driver, who was nervous, drove away.

Police spokesman Sgt.Todd Rolfson said the impersonator seems to have gone to a lot of trouble to appear to be an officer.

"If in fact this is true, it is very concerning," he said. "We have an individual here who has taken the time and effort to put blue and red lights in the grill of his car. He has purchased a white Crown [Victoria], an unmarked, and we certainly use those in the Calgary Police Service."

The suspect is described as white, 20 to 30 years of age, medium build with a ring in his ear and nose. He was wearing a dark-coloured toque.

Police said every officer, even those wearing plain clothes, carries identification and should present it upon request.

"If a driver is not sure about a vehicle that is pulling them over, they should call 911," police said.