The video shows SS officer Walter Gieseke overseeing the construction of a 1,000 mile road where thousands of prisoners died from exhaustion or were shot.
Senior officers are seen drinking tea, chatting and smoking as they order the weak and emaciated prisoners to carry out back-breaking work.
After the war Lieutenant Colonel Gieseke denied involvement and insisted he was nothing more than a pen-pusher on the project.
He was quizzed by war crimes investigators but was never prosecuted due to a lack of evidence and died a free man in 1974.
But the previously-unseen film – taken by fellow SS officers – clearly shows him overseeing construction of the road in occupied Ukraine, known as The Street of the SS.
Amazingly, the film reel has laid undisturbed for decades before it was spotted among a pile of rubbish during a clean-out of Cullompton Baptist Church in Devon in 2006.
It was handed to historian Dr Harry Bennett, who has spent the last five years studying the film and identifying those involved in the abuse of prisoners.