Colin Farrell has spoken of his horror at the allegations of sexual harassment and assault made against Harvey Weinstein, and his hope that changes will be made.

The actor, who will next be seen in dark drama The Killing Of A Sacred Deer, described the accounts of abuse as “atrocious”.

Arriving at the film’s premiere at the BFI London Film Festival, he told the Press Association: “It’s horrific, it’s just mad. I’m just watching it unfold and then tearing myself away from it and realising the horribleness of it all and the wrongdoing, fundamentally, around the whole thing and just wish healing for everyone and that changes are made.

Harvey WeinsteinHarvey Weinstein (Ian West/PA)

“I hope anyone who was hurt that they have healing, it’s just atrocious really.”

In his new film, Farrell plays a surgeon and father to two children who is forced to make a horrific decision after inviting a teenage boy into his home.

The film, directed by Yorgos Lanthimos – who Farrell worked with on The Lobster, took its toll on the star.

He said: “I was a bit depressed by the end of this one.

“If you scream into the wind for 14 hours you’ll feel insane for at least another seven after that, it will take a while to calm down.”

“If you do this kind of material, that’s as bleak as this, I don’t want to say the mood on the set was sombre, Yorgos creates an environment that’s quite calm, more quiet than any other film set I’ve worked on, but it’s just the tone of the character.

“We shot quite a lot of it in continuity so the story unfolded in you and by the end of it there’s a fairly bleak choice that has to be made, and the onus was on my character to make that choice so you bring a little bit of it home with you.”

Asked how he coped with the subject matter, he said: “I smoked many cigarettes at 3 or 4 in the morning in my pyjamas outside the hotel in Cincinnati.

“Literally I would come out of the hotel and go down this little lane down the side of the hotel to have a cigarette in my pjs and slippers.”

:: The Killing Of A Sacred Deer is released in UK cinemas on November 2.