Shot on location at Plas Pontfaen manor house in Newport, Pembrokeshire, with additional exterior shooting in the Pembrokeshire town of Saundersfoot.
The song playing on the record player which disrupts the lead character's sleep throughout the movie is "In the Evening by the Moonlight". The version used in the film is a 1926 public domain recording by The Peerless Quartet who are considered the most commercially successful vocal group of the acoustic recording era.
In Germany the film was re-titled "Das Haus des Raben", translated into English as "The House of the Raven".
In the original script the Fallen Angels mentioned by Agnes actually appear at the climax of the film. This scene was shot but omitted from the final cut.
In the original script, the song playing on the record player was written to be the 1956 version of "In the Still of the Night" performed by The Five Satins, but the licensing rights were too expensive and the filmmakers opted to use a public domain recording in the completed film.