Alfred Hitchcocks forgotten Holocaust documentary

In 1945, director Alfred Hitchcock, embarked on a difficult film project: Documenting the Nazi atrocities in liberated concentration camps across Europe. It included horrifying scenes from BergenBelsen, which was liberated by British troops in April 1945. The film, German Concentration Camps Factual Survey, was to be a lesson for all mankind. The powerful film was lost and forgotten for 70 years.