Hitchcock's iconic horror film Psycho was supposed to be a comedy The revelation promises to end decades of speculation among film buffs, who have long-argued about whether the movie was supposed to be a dark comedy or a "full-on" horror flick. Discussing the film on TV show Monitor in July 1964, Hitchcock said: "I once made a movie, rather tongue-in-cheek, called 'Psycho'. A lot of people looked at this thing and said what a dreadful thing to do, how awful, and so forth. The content as such was, I felt, rather amusing and it was a big joke. I was horrified to find that some people took it seriously. The interview features in Alfred Hitchcock: In His Own Words, an audiobook re-released this week to co-incide with today's premiere of Hitchcock, the new Hollywood biopic starring Anthony Hopkins. Psycho, said to be Hitchcock's greatest-ever film, was adapted for the big screen from a novel based on the life of American serial killer Ed Gein. It has grossed an estimated £52million worldwide since its US release in 1960. But Hitchcock says the film was never intended to be a 'proper' horror movie. He saw himself as a "switchback railway (rollercoaster) operator" who wanted to leave audiences "giggling with pleasure." He told the interviewer: "It was intended to cause people to scream and yell and so forth, but no more than screaming and yelling on a switchback railway. I'm possibly in some respects the man who says in constructing it, 'how steep can we make the first dip?' If you make the dip too deep, the screams will continue as the car goes over the edge and destroys everyone. Therefore you mustn't go too far because you do want them to get off the switchback railway, giggling with pleasure. A spokesperson for AudioGo, previously known as BBC Audiobooks, said: "Hitchcock's true intentions for Psycho have been the centre of debate since the '60s. This fascinating archive interview appears to suggest that Hitchcock had always intended Psycho to be comedic, rather than terrifying. Alfred Hitchcock: In His Own Words is available from www.audiogo.com/uk.