Italian film-maker Giulietto Chiesa, who was in Berlin for a screening of his documentary which questions the official US version of the 9/11 terrorist attacks, has called for an international tribunal to probe events.
Federal Aviation Administration controllers, US Air Force pilots, military commanders and physicists also appear in the critical documentary, which the director hopes will create "political awareness" of the "faulty" official investigation into the events by the 9/11 Commission.
"Some of the individuals appearing in the film are former FBI and CIA agents, people who have in a sense taken a very big risk in speaking out. I am very grateful to them because they have done a big job," said Chiesa.