BERLIN — The workers came from across Europe to pack boxes for the online retailer Amazon at distribution centers in Germany during the Christmas rush. They did not expect to be watched over — some say intimidated — by thugs in neo-Nazi-style clothing and jackboots.

On Friday, Amazon said it was investigating claims made in a documentary that a subcontractor employed security guards with neo-Nazi ties to oversee the immigrant workers.

The documentary, broadcast Wednesday on the ARD public television network, showed guards in black uniforms with H.E.S.S., after Hensel European Security Services, but also the last name of Hitler’s deputy, Rudolf Hess, emblazoned on their chests.

According to the film, security guards employed by the subcontractor scared and intimidated hundreds of temporary workers from Hungary, Poland, Spain and other European countries.