SUN PRAIRIE, Wis. -- Sun Prairie police said on Monday that they have concluded an investigation into a recent officer impersonation complaint and found that the traffic stop was conducted last week by a legitimate officer.

The complaint came from a driver who was pulled over on suspicion of speeding on Aug. 24 on the southbound portion of Highway 151, near the Sun Prairie exit. The driver said the officer identified himself as a private investigator.

Initially, Sun Prairie police said they weren't able to find an officer who had made the stop.

The officer who conducted the stop has since reported that he did stop the vehicle using his red and blue emergency lights. He said he fully identified himself as a state investigator and gave the driver a warning for speeding. The officer said he was wearing his badge and other equipment on his belt at the time, police said.