Martial Matthieu, the alleged collaborator to the script, does not exist. This name is an alias for Claude Chabrol himself.
A few scenes were filmed in the country house of André Ciganer, the father of French ex-first lady, Cécilia Sarkozy. The latter, aged 4, appears uncredited as the little girl in white.
A major box-office failure, this proved a serious setback in the directing career of Claude Chabrol. However, it is generally regarded as one of his finest films.
Stéphane Audran, the woman who plays Hélène, married Claude Chabrol, the director, in 1964 (and divorced in 1980).
French visa # 25363 delivered on 2-5-1962.