Lesley-Anne Down married assistant director Enrique Gabriel during filming. It was his first and only, and her first of three marriages. They divorced about one year later without offspring.
Sphinx (1981) was budgeted at $11 million with an expected 13-week shooting schedule, including five weeks of filming in Egypt at Cairo and Luxor. More than $1 million was spent on the interior sets built at the Mafilm Studios. It took six months to create these "vast sets," including a replica of King Tutankhamun's tomb and the undiscovered tomb of Seti I, with approximately 900 recreated artifacts. A negative, containing approximately 30 minutes of footage featuring a boat sequence in Luxor, disappeared in transit to Cairo, Egypt. But due to "international tensions," the incident was kept quiet.
Interiors were filmed in Budapest. Egypt locations include the Cairo bazaars, Giza, the Winter Palace Hotel in Luxor, and Thebes. The tomb film set cost $1 million.