Zac Efron struggled to separate himself from his serial killer character Ted Bundy

Actor Zac Efron has revealed that it became difficult for him to detach himself from his "Extremely Wicked, Shockingly Evil and Vile" character Ted Bundy after he finished shooting for the film.

The biographical crime thriller, directed by Joe Berlinger, features Efron as serial killer Bundy, who confessed to killing at least 30 women during 1970s.

On the sidelines of the film's premiere here, Efron told Metro, "I've never played a role in which I really have to separate myself from when I go home at night and it was almost impossible. I'd like to say that I did it successfully but I couldn't."