Hollywood superstar Tom Cruise was the inspiration for Christian Bale's frightening portrayal of a bloodthirsty maniac in American Psycho, according to the movie's director Mary Harron.

The Dark Knight actor took on the role of Patrick Bateman in the 2000 thriller, playing a wealthy young investment banker who apparently leads a double life as a vicious multiple murderer, reports hollywood.com.

Director Harron has revealed Bale based the character's smarmy persona on Cruise after seeing the Hollywood superstar give an interview on a US TV channel.

"We talked about how Martian-like Patrick Bateman was, how he was looking at the world like somebody from another planet, watching what people did and trying to work out the right way to behave," she said.

"And then one day he called me and he had been watching Tom Cruise on David Letterman, and he just had this very intense friendliness with nothing behind the eyes, and he was really taken with this energy," she added.