Unbroken: Angelina Jolie movie left actor physically sick and unable to stop crying

Miyavi stars as a cruel sergeant in the upcoming Louis Zamperini biopic

A still from Angelina Jolie's 2014 war drama Unbroken (Rex Features)

It sounds like Angelina Jolie's upcoming film Unbroken is going to be pretty darn intense after one of her actors threw up and "couldn't stop crying".

The US actress turned director is working on a movie about the late Louis Zamperini, the Olympic runner who was taken prisoner by Japanese forces during World War II, and it looks set to include plenty of graphic violence.

Miyavi, the Japanese pop star starring as cruel sergeant Matsuhiro Watanabe, has spoken about the harrowing experience of working on the project.

He was encouraged by Jolie to immerse himself into the mindset of a man accustomed and desensitised to violence. In one scene, Miyavi's character brutally beats Zamperini, played by Jack O'Connell.

"It was awful torture for me to hate the other actors," the 33-year-old told Vanity Fair. "I had to have hatred for them. When I had to beat them, I had to think about protecting my family.

"At the same time, I didn't want to be just a bad guy. I wanted to put humanity in this role. [Matsuhiro] was both crazy and sadistic, but also weak and traumatised."

Miyavi, real name Takamasa Ishihara, added that Jolie wanted to "make a bridge between all countries that had conflict".

"She was very persuasive," he said. "It's a story that is still painful for my country and after filming some of the more violence scenes, I couldn't stop crying."

Jolie became close with Zamperini shortly before his death aged 97 last July, and was sure to show him an early cut of Unbroken.

"I was more emotional than he was," she said. "I went in to take care of him and he was taking care of me. It was an extremely moving experience, to watch someone watching their own life."

Jolie is currently directing her husband Brad Pitt on romantic drama By The Sea, about a married couple going through some difficulties.