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).
Lawrence made John Derek a co-producer to entice Ursula Andress into performing a nude scene, which was intended for the opening sequence where Aldo Ray assaults her (although in the final film, the sexual encounter is consensual).