Natalie Portman reveals sick reality of life as a child star

Natalie Portman speaks onstage at 2018 Women's March Los Angeles at Pershing Square on January 20, 2018. Photo / Getty

Natalie Portman has revealed how she experienced "sexual terrorism" when she was 13 after a fan sent her a "rape fantasy" and critics discussed her "budding breasts".

The Oscar-winning actress shared her traumatic experience as she addressed the Los Angeles Women's March.

The 36-year-old told how she turned 12 on the set of her first film Leon: The Professional, where she played a young girl who befriended a hit man in hopes of avenging the murder of her parents.

When the movie was released a year later, she described feeling excited to open her first fan mail but was left horrified when she opened it to find a letter from a man who had written a "rape fantasy" about her.

She went on to tell the crowd: "A countdown was started on my local radio show to my 18th birthday, euphemistically the date that I would be legal to sleep with.

"Movie reviewers talked about my budding breasts in reviews. I understood very quickly, even as a 13-year-old, that if I were to express myself sexually I would feel unsafe and that men would feel entitled to discuss and objectify my body to my great discomfort."

She said from then on she had adjusted her personal and professional behaviour to avoid this happening, and even went as far rejecting roles with kissing scenes.

Portman would try to bolster her "bookish and serious" side and built a reputation as being "prudish, conservative, nerdy and serious".

Natalie Portman. Photo / Getty

She said: "At 13 years old, the message from our culture was clear to me. I felt the need to cover my body and to inhibit my expression and my work in order to send my own message to the world that I'm someone worthy of safety and respect.

"The response to my expression, from small comments about my body to more deliberate statements, served to control my behaviour through an environment of sexual terrorism."

Portman joined hundreds of thousands of women at marches across the US on the anniversary of Donald Trump's presidency.