The incident happened shortly before 5:00 p.m. Thursday on Stokes Road between Branin and Himmelein roads in Medford Township, New Jersey.
The 17-year-old driver said she was pulled over by a dark-colored, older model car with a siren and rotating blue lights.
She said a man got out of the car and approached her vehicle, then asked for her driver's license - and a date.
He said 'Oh, you're an attractive young lady. I thought maybe I could get your phone number,'" said Lt. Jeffrey Wagner of the Medford Twp. Police Dept.
He started to question the girl, and took her ID, at which point he told her he was not a police officer.
"He again asked, 'If I give your wallet back can I get your phone number?' She said no, took [the wallet] and pulled away," said Lt. Wagner.
The suspect is described as a white man in his 30s, about six feet tall with a thin build. He had short brown or dirty blond hair. He was wearing a navy blue t-shirt and blue pants with a yellow stripe on each side.
Anyone who can provide information is asked to contact the Medford Township Police Criminal Investigations Bureau at 609-654-7375 or the Confidential Citizen Tip Line at 609-714-0302.
Medford authorities say that most police cars in town are clearly marked on the sides and have red and blue flashing lights. Also, real officers will have a visible badge, a belt with a gun, handcuffs and other gear.