The German Defence Ministry is investigating an amateur video clip of a German army instructor ordering a recruit training with a machine gun to imagine he is firing at "African Americans" who are insulting his mother.

German television networks on Saturday aired the video clip.

"You're in the Bronx, a black van pulls up in front of you and three African-Americans get out and start really insulting your mother ... now do something!" the instructor says in German while a recruit lying on the ground starts firing his gun.

The instructor in the grainy 90-second video, which Stern magazine online's edition said it found on the internet, then tells the recruit he wants to hear screaming swear words each time the recruit fires his weapons.

A spokesman for the army at Rendsburg in the northern state of Schleswig-Holstein confirmed that the incident had taken place in July and that the instructor had since been transferred to another position. The Defence Ministry is investigating.

The spokesman said it was a "one-off incident". The German army has had to deal with a number of embarrassing scandals in recent years that have damaged its image.

Bundeswehr soldiers in Afghanistan took pictures of each other desecrating human skulls while on patrol outside Kabul. They were published in newspapers last year and the soldiers were suspended.

In 2004, German army recruits were subjected to torture and electric shocks at one base in unorthodox training to prepare them for being taken hostage. The instructor was suspended.

Reuters