The Puzzle of the Red Tassel(1963)

Original title: Das Rätsel der roten Quaste

Secret agent Richard Warren poses as a journalist in Caracas to sell a secret uranium formula. A dancer named Sylvia approaches him and warns him of danger. A short time later, the young woman is dead. Richard finds her body, with a red tassel lying next to it. The secret agent is suspected of murder and flees. He finds shelter with the attractive Regina, but she apparently harbors a secret ...