The titular dalek was operated by three people. One actor was inside the dalek casing to move and rotate the body. A second was moving the head and eye stalk and operating the lights by a radio controlled remote. The third was performing the voice and gesturing to the remote control operator to time the lights with the voice. In the original series, "Doctor Who" (1963), the daleks had only two operators; one performing the voice and the actor inside the casing doing everything else.
Michael Brandon was asked to play Van Statten but was not free.