Angelina Jolie: 'My kids saw me in pain on movie set'

Angelina Jolie has revealed her children saw her in "a lot of pain" on the set of her new movie Maria.

The actress plays opera singer Maria Callas in the new biographical drama written by Steven Knight. Angelina's sons Maddox and Pax worked as production assistants on the movie, and the star has recalled how the experience allowed them to see her in a "new way".

"The character (Callas) has a lot of pain and they've of course seen me go through a lot of things, but they hadn't experienced me expressing a lot of the pain that usually a parent hides from a child," Angelina explained in a new interview with BBC News.

"So they were there to witness some of that, but then we would hug or they would bring me cups of tea."

Maria follows the story of the famed opera singer in her final years, when she retreated to Paris during the 1970s.

The US-born Greek soprano was one of the biggest stars in the opera world, but her vocal decline led to a premature end to her career and she died aged just 53.

Elsewhere in the interview, Angelina revealed that undertaking seven months of training to get her singing voice ready for the role was "very physically demanding".

"We started with regular singing classes and it was challenging in many ways," she explained. "But when the opera classes began, what it requires with your breathwork and your body and just the force of what you push through yourself, it's just a very different physicality."

The 49-year-old star has admitted she was "actually quite shy" about singing in the film, and has joked that Pax witnessed her "early horrible days" as he was there to record her initial singing practice.

"It's always good for your children to watch your mum not do something easily, but swear and fight and fail and have to try again," she shared. "So that's an important and beautiful thing."