Lawrence made John Derek a co-producer in order that his then-wife Ursula Andress would do a nude scene. He says this would be in the scene at the beginning "when Aldo Ray rapes her" (although in the final film the sex is consensual).
To get Ursula Andress to participate in a nude scene, Lawrence made John Derek a co-producer. This scene would be part of the initial sequence where Aldo Ray rapes her, but it was ultimately changed to a consensual encounter in the final film.