Jess Franco made another Edgar Wallace movie, Sangre en mis zapatos, which was based on Sanders of the River. This is based on the story Keeper of the Stone, which is from the same book.
Prof. Walter Forrester (Ángel Menéndez) is a British scientist working in the Akasava jungle in South America who has disappeared and may have stolen a mysterious stone. His nephew Rex Forrester (Fred Williams) is looking for his uncle. But the real reason to watch this is British agent Jane Morgan (Soledad Miranda), who has a secret identity as the stripper wife of the British consul Irving Lambert (Alberto Dalbés), which seems pretty wild when you wrap your mind around it.
The sinister Dr. Andrew Thorrsen (Horst Tappert) and his perhaps even more nefarious wife (Ewa Strömberg) also get involved, Franco plays an evil agent and Howard Vernon gets blown up real good when he tries to steal the stone, which can turn people into zombies and metal to gold because, well, who knows. It’s all a device to get us to see just how wonderful Soledad could be as a spy.
Sadly, she’d die in an auto accident at the too soon age of 27 soon after this movie wrapped. I wasn’t even born yet and it still breaks my heart.