Police are investigating accusations that security guards at an asylum center in western Germany repeatedly abused refugees physically and mentally.

A police spokesman said Sunday that police raided the center in Burbach near the city of Hagen and questioned both security guards and refugees after a local journalist received a DVD showing the abuse of an asylum seeker by security guards.

Spokesman Ulrich Hanki said police also found a picture on a guard's cell phone showing a security officer pushing his foot against the neck of a handcuffed refugee lying on the floor.

Hanki said other refugees had come forward and reported further abuse and that all the guards, who belonged to a private security company, were withdrawn from the center.

Police and prosecutors are investigating possible xenophobic motives.