A German policeman was nabbed for a bank robbery after he used his girlfriend's car for the heist, authorities said Thursday.

By using his girlfriend's car, he "might as well have left his business card, it was really stupid," said Horst Roos, spokesman for state prosecutors in the western city of Trier.

Police quickly discovered the boyfriend of the car's owner was on the Trier police force, and recognized their colleague's likeness in video footage of the masked robber.

When the 52-year-old heard he had fallen under suspicion, he confessed -- just a day after the armed raid.

He said he stole the money -- more than 10,000 euros ($12,430) -- because he was in financial trouble, Roos said. Armed robbery carries a minimum jail sentence of five years in Germany.