"This is a very positive step, we welcome the arrest, I hope this will only be the first of many arrests, trials and convictions of death camp guards, " the Simon Wiesenthal Center's Efraim Zuroff told AFP news agency.

BBC: Germany arrests 'former Auschwitz guard' Hans Lipschis

There are also guards out on the desert camp where the British are.

BBC: Middle East correspondent Frank Gardner

Since that time, Stone has radically reshaped the camp, working to change the attitudes of the guards and detainees alike.

CNN: Behind the Scenes: Walking amid 2,000 al Qaeda suspects