The new trailer for Zac Efron's Ted Bundy is so harrowing

The trailers alone have been giving us nightmares, and now the star of the terrifying new Ted Bundy biopic, Zac Efron, has revealed he had found it 'impossible' to let go of the role of the notorious US serial killer after he stepped off set.

Speaking on the red carpet of the London premiere of the harrowing new film, Efron confessed to Daily Mail reporters that taking on the part had proved a challenge for his mental health.

"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," he explained. "I’d like to say that I did it successfully but I couldn’t."

Efron also admitted that taking the lead as the infamous murderer and rapist in the Netflix thriller wasn't a role he had ever envisaged himself playing in his career.

"I really wasn’t interested in playing a serial killer, I’m not in the business of glamorizing a horrendous person or his acts, but there is something unique about the way we went into the psyche of Ted, and his longtime girlfriend Liz [played by Lily Collins]," Efron said.

"It’s a different perspective and not your run-of-the-mill serial killer cliché, body count gets higher and higher and oh the guy you always knew did it, did it. This is what it was like to be there on the day, we didn’t know if he was innocent or guilty, we just saw Ted Bundy through their eyes."

Based on the memoirs of Ted Bundy's longtime partner Liz, the new Netflix film Extremely Wicked, Shockingly Evil and Vile chronicles the multiple murders of the notorious American serial killer as she fights to determine the truth about her evil boyfriend.

The first teaser trailer dropped earlier in the year, and many fans had reservations about the glamorisation of the infamous murderer, which Zac Efron addressed in an interview with Variety earlier in the year.

"I feel a responsibility to make sure that this movie is not a celebration of Ted Bundy," he clarified. "Or a glorification of him. But, definitely, a psychological study of who this person was."

If the first trailer depicted Bundy's charismatic appeal and handsome looks instead of the women he murdered, the new trailer take a far darker turn.

The two-and-a-half minute clip focuses on Bundy's heinous crimes, the misguided public fascination at trial, as well as the psychological toll the proceedings took on his long-time partner, Elizabeth Kloepfer (played by Lily Collins).

The infamous serial killer was responsible for the gruesome kidnap and murder of around 30 women and girls during the 1970s, which he was eventually executed for in 1989.

Directed by Oscar-nominated documentary filmmaker Joe Berlinger, who created the four-episode true crime docuseries [i]Conversations With a Killer: The Ted Bundy Tapes[/I] for Netflix earlier this year, the new biopic premiered to rave reviews at Sundance.

Extremely Wicked, Shockingly Evil and Vile premieres May 3 on Netflix.

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