US actress Julia Roberts has said, "We're losing the art of conversation in humanity", as she premiered a new film about sexual assault, which is likely to divide audiences.

After The Hunt, which has just launched at the Venice Film Festival, follows a student at Yale University who accuses a college professor of rape.

Neither the student's nor the teacher's version of events is presented as entirely credible, and the film casts doubt on both sides.

Roberts acknowledged the movie would provoke debate, commenting: "We are challenging people to have a conversation and to be excited by that or to be infuriated by that, it's up to you."

She added, "There's a lot of old arguments that get rejuvenated in this movie in a way that does create conversation."

Roberts plays college professor Alma, who is caught between a star pupil named Maggie (Ayo Edebiri), and one of her fellow teachers and friends, Hank (Andrew Garfield).

When told that several female journalists came out of the press screening questioning the morals of the film, Roberts replied: "That's how we wanted it to feel.

"Everyone comes out with these different feelings, emotions and points of view. And you realise what you believe in strongly and what your convictions are, because we stir it all up for you."

After The Hunt is likely to prompt similar discourse when it is released by Amazon later this year, and it could be seen as controversial for the ambiguity surrounding the student's testimony.

The film does not take a clear stance one way or the other, Roberts noted. "It's not so much that we're making a statement, we're just sharing these lives for this moment, and then want everyone to go away and talk to each other."

She added: "That to me is the most exciting bit, because we're kind of losing the art of conversation in humanity right now, and if making this movie does everything, getting everybody to talk to each other is the most exciting thing we could accomplish."

The film is directed by Italy's own Luca Guadagnino, whose previous credits include Call Me by Your Name, Challengers and A Bigger Splash, while the script is written by actress Nora Garrett in her screenwriting debut.

"There was so much rich complicatedness in all the characters, and that's just the dream," recalled Edebiri, best known for TV series The Bear.

"Being challenged by the type of character in the best way, by each other, that's just how you grow and that's the kind of movie I really enjoy watching. Something where you're just like, 'I have to go back', because maybe the vantage point I had at the beginning is completely different at the end."

At different points of the film, Alma leans towards different sides, as she learns more information from both parties.

But Roberts rejected the suggestion that her character's partial support of Hank and doubting of Maggie revives a damaging anti-feminist narrative.

"I don't necessarily think it's reviving just an argument of women being pitted against each other or not supporting each other," she said. "There's a lot of old arguments that get rejuvenated in this movie in a way that does create conversation."

As more information comes to light throughout the film, Alma realises elements of her own history may have influenced the way things have unfolded.

Roberts has been praised by critics for her role in the film. The Telegraph's Robbie Collin described it as "her best performance in years" while the Times bullishly predicted an Oscar win.

But many critics took issue with the film as a whole. Screen Daily's Nikki Baughan said the film "puts itself well before any real and valuable discussion of these deeply complex issues".

"While it may wish to spark debate," she continued, "the stance it takes on its messaging is troubling."

The film's director and screenwriter "seem convinced this is all very provocative, very new with its hard questions and subjective truths," noted the Hollywood Reporter's David Rooney.

"But frankly, it's very five years ago, which makes it more punishing."

IndieWire's Ryan Lattanzino said that while Guadagnino is "one of the best filmmakers working", the film "ultimately isn't against-the-grain enough", adding: "It strives for moral ambiguity, but ends up startingly morally stark."

Garfield is best known for Spider-Man and The Social Network, and has previously been Oscar-nominated for Hacksaw Ridge and Tick Tick Boom!

The British actor said there was something inherently human about the flawed nature of the characters, which is partly what attracted him to the project.

"I feel like, when our motivations are invisible, even to ourselves, all of us are unreliable narrators," he said.

"Especially in a culture where a perception of survival is paramount. And as we all know, human beings will behave animalistically when we are put in a position where we believe it is life or death.

"And I found that really interesting about this world, these characters, and how their drives, wants and needs are invisible to themselves in certain ways, and they are convincing themselves they are the hero of this story."

Guadagnino, who is back on form after directing last year's poorly received Queer, agreed: "I think it's always interesting to see what we carry without knowing we carry it within ourselves.

"And to see that happening in the confrontation between characters, it's fascinating. I think even the lies of people tell the truth."

Roberts, who has previously starred in Pretty Woman and Notting Hill and won an Oscar in 2001 for Erin Brockovich, said she enjoyed the opportunity to play troubled women.

"Trouble is where the juicy stuff is, right?" she smiled. "It's all that great complexity.

"It's like dominoes of conflict, once one falls, everywhere you turn there's some new piece of conflict and challenge, and that's what makes it worth getting up and going to work in the morning."