At 19, Elle fell in love with an older man. Then, one day, he told her to "get to work".

At 19 years old, Elle Snow thought fate had brought her new boyfriend into her life – but it was something far more sinister.

The Californian woman was eventually separated from her family and forced in to sex slavery, but in the beginning, she just thought she’d met a nice, older guy.

After bumping into him a few times, Elle thought it was “fate” that had brought them together, not realising he’d planned it that way.

“I met my trafficker the same way a lot of us do,” she told CNN.

“You always hear, ‘I met a guy.’… I didn’t realise that I had been marked.”

Things moved fast in Elle's new romance. Her boyfriend, David Bernard Anderson, who'd met her family, invited her on a trip to Sacramento, 500km away from her home in Humbolt County.

The next morning, she woke up to find the man holding a pair of high heels and pink skirt standing in front of her, telling her to "get to work".

"I told him 'I'm on vacation, like, what are you talking about?' And he's telling me 'you're not you anymore. This is not your name. Your name is now 'Angel.'" she said.

Anderson, who revealed himself as a pimp, had taken her keys, phone and clothes - making leaving hard, but not impossible - until he threatened to hurt her 14-year-old sister if she left.

"There was no way to get out of this situation. He took my clothes, my shoes, my keys, my phone, and eventually he started saying he is not who he said he was, that he's actually a pimp, and this is how prostitutes are made."

Elle was forced into sex work around San Francisco for the next eight months, often trying to escape. One failed attempt ended with her "beaten bloody" for hours.

Thankfully, Elle's story didn't end there. She managed to escape with help from a friend and went on to testify in court in 2014 against her Anderson, who was on trial for trafficking a 16-year-old. He was sentenced to nine years jail.

Now, Elle leads an anti-trafficking charity called Game Over, which she founded in 2016. It's aim is to protect girls from going through the horror she went through by exposing what she calls "the game" of sex trafficking to the world and working to shut it down.

She looks for signs of trafficking in sex workers and also trains police to talk to local schools about the issue.

"If you're putting posters everywhere and everybody's talking about it and they're saying, 'Hey, I know what a pimp is. I know those books.' Then all of a sudden the traffickers don't feel comfortable anymore," she told CNN.