According to the commentary by John Hurt on the DVD, real-life retired executioner Albert Pierrepoint was a technical advisor for the execution scene. This scene was the first British people had seen in a cinema of a British hanging, and as it was still covered under the government's Official Secrets Act, no details regarding the scene were available. This is where Pierrepoint came in, under an assumed name, and was able to re-create the harrowing scene to maximize the true terror of what it must have been like.