Actress and model Frida Farrell has shared her ordeal of being kept as a s** slave for three days in a Harley Street flat to help other victims of s** exploitation.

Ms Farrell marked the 15th anniversary of her kidnapping by warning women to take precautions against trafficking.

In an interview with The Independent and London Evening Standard, she spoke about her three-day kidnap ordeal during which she was forced to have s** with a series of unknown men.

She was afraid her kidnapper would find her if she came forward afterwards, and so was silent for 10 years.

Ms Farrell called on women to be cautious, particularly when going to someone’s house for a photoshoot.

She advised people to “bring a friend and make sure people know exactly where you are, so that if you’re not back in an hour they can report it.”

Ms Farrell co-wrote and acted in the award-winning film, Selling Isobel, based on her experience.

Following the release of the film, she said she has received messages and emails from other victims saying “something similar happened to me” or “I was raped”.

She called the joint campaign by The Independent and the Standard to widen our knowledge of modern slavery admirable, stating that s** exploitation had become a problem that’s quickly grown larger than we can comprehend.

Ms Farrell was approached near Oxford Circus after a shopping trip one September night in 2002 by a man who said he wanted to cast her in a photoshoot.

She showed up and as the photographer took a series of shots all seemed well.

But when she arrived at his flat the next day, there was no longer a photo studio inside.

The photographer’s demeanour had changed.

He slammed the door behind her, locked it, and put the key in his pocket.

He pulled out a hunting knife and held it by his side, almost as if to say, “I have this. Don’t f***ing do anything.”

He told her to put on a set of lingerie and offered her some milk, which she suspected was drugged.

“I thought I’d rather just drink the milk and not live to see what’s going to happen,” she said.

“I didn’t know if he was just a crazy man who was going to murder me, rape me or hit me, so I just drank the milk and thought ‘God help me’.” She woke up in a different flat and, over the next three days, at least six men abused her while she pleaded for help.

Her captor also assaulted her.

But on the third day he left the flat without locking the door.

She fled and didn’t stop until she was past Bond Street.

She told police a few days later, but today still doesn’t know if her captor was ever found.

Ms Farrell wants similar victims to feel unafraid to approach police, friends, family or therapists to tell their stories.

“I was so scared because I was embarrassed, and I blamed myself, which is stupid.

“But I took some time, and now I’m coming out and talking about it, and it’s helping,” she said.

“I thought if there’s just one woman who could have been saved before it happened because she was educated about it, then my job would have been done.”

This autumn, Ms Farrell is taking Selling Isobel to the San Diego film festival, with a theatre run planned for London and Los Angeles.