The producers were sued for their unauthorized use of footage from an authentic silent ethnographic film that had been released about 15 years earlier. Some footage was purloined from footage shot in 1915 by Lady Grace Mackenzie. When this fact came to light, her son Byron P. Mackenzie sued the producers for the footage and was awarded $150,000 in damages.
Hollywood's famed "gorilla performer," Charles Gemora, admitted that he played the gorilla in this film. Gemora had already played gorillas in about 10 films before this. He would continue to play gorillas, and perform in other monster costumes, until the late 1950s.
Some of the native women were reportedly played by white actresses in blackface.
The outrage over the film grew to the point where the Federal Trade Commission launched an investigation. Their findings were that much of the film had been faked and that the "best scenes" had been filmed at the Los Angeles Zoo. They also concluded that the two British explorers, Sir Hubert Winstead and Captain Daniel Swayne, "were both fictitious persons not existing in fact."
Doubts about the authenticity of this "documentary" arose during the California previews when one of the "natives" was recognized as a black actress who was known at Central Casting.