Brooke Shields has revealed that she was raped when she was in her early 20s, but was too ashamed to tell anyone at the time.

The actress, 57, told the dark story in her new documentary, Pretty Baby, which explores abuse of young, vulnerable people in Hollywood.

Shields, a child star, appeared in the film Pretty Baby aged 11, and appeared naked with 29-year-old Keith Carradine.

At 15, she appeared in two more films, Blue Lagoon and Endless Love, that included sex and nudity.

In the documentary, which premiered at the Sundance Film Festival on Friday, Shields told of being attacked shortly after graduating from Princeton in 1987.

Detailing the rape for the first time, Shields says in the documentary that she was trying to get back into Hollywood after attending Princeton, and had dinner with a man she knew to talk about potential projects, according to Entertainment Weekly.

The man - who Shields does not name - then invited her to come back to his hotel and call a taxi.

'I go up to the hotel room, and he disappears for a while,' she said.

She said there was a pair of binoculars in the room, and she picked them up to watch some volleyball players out of the window.

He then returned to the room naked, and attacked her.

'I put the binoculars down and he's right on me. Just like, was wrestling,' she said, explaining that she didn't fight out of fear.

'I was afraid I'd get choked out or something.

'So, I didn't fight that much. I didn't. I just absolutely froze.

'I thought one 'No' should've been enough, and I just thought, 'Stay alive and get out,' and I just shut it out. 

'God knows I knew how to be disassociated from my body. I'd practiced that.' 

She said she left the hotel after the attack, got in a cab and 'cried all the way to my friend's apartment.'

She said it took her years to come to terms with what had happened.

'He said to me, 'I can trust you and I can't trust people.' It's so cliché, it's practically pathetic,' she said.

'I believed somehow I put out a message and that was how the message was received.

'I drank wine at dinner. I went up to the room. I just was so trusting.'

After the incident, Shields recalled phoning her friend and security head Gavin de Becker, who told her: 'That's rape.'

She replied: 'I'm not willing to believe that,' and has not spoken of the incident publicly until now.

She said she wrote to her attacker years later, but he never responded.

'I just threw my hands up and said, 'You know what, I refuse to be a victim because this is something that happens no matter who you are and no matter what you think you're prepared for or not,'' she said.

'I wanted to erase the whole thing from my mind and body and just keep on the path I was on.

'The system had never once come to help me. So, I just had to get stronger on my own.'

The two-part documentary is directed by Lana Wilson, who is best known for helming Taylor Swift's 2020 Netflix documentary Miss Americana.

The movie, which earned Shields a standing ovation at Sundance, also chronicles the media's later obsession with her virginity, her mother's alcoholism, and her first marriage to tennis star Andre Agassi. 

It will be available on Hulu later this year.

The revelation - which echoes #MeToo revelations by prominent and lesser-known Hollywood actresses in recent years - is one of several shocking moments in the film, which will be released in two parts.

Part one examines the intense sexualization Shields experienced as a young girl, including a provocative nude photoshoot at age 10, and her appearance as an child prostitute in the film Pretty Baby at age 11.

The documentary shows a young Shields being asked lascivious questions by much older male chat show hosts about her roles in movies such as The Blue Lagoon and Endless Love, and the series of controversial Calvin Klein jeans commercials she starred in.

After experiencing global fame as a teenager, Shields attended university at Princeton, and initially struggled to find acting roles again after she graduated - leading to the meeting with her alleged rapist.

'My personal message is perseverance, and not allowing yourself to become a victim to a society or an industry,' she told AFP ahead of the film's premiere at the festival in Utah.

'I'm proud of how I kept learning, kept growing, kept striving and kept loving what I do,' Shields said.

It features several of Shields' famous friends including Lionel Richie, Laura Linney and Drew Barrymore.