 This, along with the fact that she was Caño's lover at the time and a language barrier due to her only speaking German and some English, led to her having antagonistic relations with Bava and Betti on set; she later successfully sued Caño for failing in his promise to make her the film's top-billed actress.At least one scene, in which John introduces Helen to Inspector Russell, was added solely to appease Lassander by giving her more screen time.Lead actor Stephen Forsyth recalled that Bava did not give him detailed direction on set.