Audrey Hepburn was aged about 50 when this movie was made and released. The character she plays was much younger and in her 30s. Writer Sidney Sheldon revised his "Bloodline" novel to accommodate the literary age of the film version's lead actress. Hepburn had been in semi-retirement when she agreed to do this picture. The DVD sleeve notes declare that this movie was one of the final films of actress Audrey Hepburn. Hepburn's salary on this movie was $1,000,000 plus a percentage of the gross.
This film was made and released about two years after its source novel of the same name by Sidney Sheldon was first published in 1977. The book was Sheldon's fourth novel whilst this movie was the second of Sheldon's novels to be filmed, the first having been The Other Side of Midnight (1977).
Exotic settings featured in the movie included Sardinia, New York, London, Munich, Paris, Rome and Switzerland. The picture was shot in at least seven cities in six countries, the latter being Italy, England, Germany, France, Denmark and the USA.
According to the article "The Secret Bloodline of Audrey Hepburn" in Slant Magazine, this film "... was made during the dispiriting close of her second marriage to the Italian playboy doctor Andrea Dotti, and she turned to it in some desperation, not realizing until halfway through shooting that there was going to be an interpolated snuff film subplot! She wanted to walk, understandably, but she honored her contract, to the dismay of her fans and admirers."
Early in the movie the curtains are drawn back in Audrey Hepburn's home and we see a busy downtown street, but later they're drawn back and there is an ocean view. At a board meeting, Romy Schneider is first seen from behind, sitting at the table with her golden hair showing, but as soon as she is seen full-face her hair is all tucked up under a turban.
The movie's director Terence Young was known for directing three of the early James Bond films of the 1960s. This picture also co-starred as the detective Gert Fröbe who had been known for playing the title role in the James Bond film Goldfinger (1964) but that early Bond film was the one which wasn't directed by Young but Guy Hamilton.