Trivia

Hazel Court played the Anton Diffring sculpting scene topless. Only her bare back is shown in the British and U.S. versions, but her breasts are visible in the scene shot for European versions. It was one of the first nude scenes of its kind to be shot in England. They cleared the set and had just a skeleton crew. She said she agreed to do it because the scene warranted the nudity and it was shot beautifully. If had been gratuitous, she'd have refused.

Anton Diffring was the second choice for the role of Georges Bonnet, after Peter Cushing turned it down shortly before filming began. When Cushing claimed illness after breaking his oral commitment, the studio threatened legal action against its biggest star but didn't follow through.

Georges Bonnet was born in 1786.

Features Hazel Court's only nude scene. She said in an interview that exposing her breasts to the male crew on set was both terrifying and exciting at the same time. From what she heard, European audiences really appreciated them and it did help ticket sales, which is why producers asked her to do it. After filming the scene, the producer had a photographer take photos of her topless, which she thought was odd, because she had no idea where they'd use them as promotional material. She joked that it was probably for the producer's private collection. Years later she started seeing them pop up on the Internet.

Largely unsuccessful upon general release, the film has garnered a cult following among "Hammer" fans.