Schwarzer Nerz auf zarter Haut (1969)

Researcher Professor Dr. Franz Hergarten has to leave his blonde companion, Lisa, back home, because, as an important keeper of secrets and courier for a certain organization, he is supposed to transport highly sensitive and important documents from Germany to New York. An ocean liner is chosen as the means of transport. German security agents are to accompany him and shield him from unwanted outsiders. Hergarten soon realizes that several agents from hostile powers, who are also eager to get their hands on the secret papers, are shadowing him and using every trick and weapon imaginable—including those of women. At first, Hergarten manages to avoid interference. Then a siren named Sybilla appears aboard, but she has no intention merely of seducing the German: she is also an agent and is initially supposed only to keep an eye on Hergarten. An even more dangerous woman seems to be another passenger—Lisa, this time dark-haired. She, too, evidently has no good intentions. Soon matters come to a head. Not only do the two women fight over Franz in order to get hold of his valuable cargo, but his male adversaries also stop at nothing, using every kind of weapon—from fists and pistols to a venomous snake.