Secret of the Sphinx (Italian: La sfinge sorride prima di morire - Stop Londra) is a 1964 film, directed by Duccio Tessari, which stars Tony Russel, Maria Perschy, Ivan Desny, and Manuela Kent. Photography was by Joe D'Amato.
Shot on location in Egypt, the story unfurls like an Italian Giallo as a group of people meet under strange circumstances, and one by one they are murdered. The soundtrack was composed by Mario Migliardi.