In 2006, Tanya Kach captured headlines across the globe after escaping from her 10-year captivity just two miles from her home in Pittsburgh.
When she was 14, Kach was abducted by her high school security guard Thomas Hose, who was 24 years older than her.
She was kept as a sex slave and confined to Hose's bedroom for the first four years, using a bucket as a toilet and never once seeing the light of day.
Kach vanished in 1996 after leaving her parent's home in McKeesport for school. Investigators had no leads as to her whereabouts and her case fell through the cracks of the system.
Unknown to police, she was being kept in the small town. The documentary shows how Hose's young son and elderly parents also lived in the house where she was kept, but were apparently oblivious to her presence.
In an interview with Dr Phil, Kach told how Hose wanted sex constantly, She said he was "perverted" and that the encounters were "very rough" and "borderline violent". Hose told her that if she tried to leave he would kill her.
When she was 18, Kach was allowed to go outside under a new identity, Nikki Allen, and was permitted to go round the neighbourhood for short periods, yet no one recognised her as the missing girl.
However, after a decade, Joe Sparico, a local shop owner contacted the police after Kach tearfully confided in him about her real identity. He recalled her saying: "My name is not Nikki Allen, it's Tanya Nicole Kach, if you go to a website for missing children, you will see me there."
Hose is now serving a maximum sentence of 15 years after pleading guilty to involuntary deviate sexual intercourse with a minor, interfering with the custody of a child and child endangerment. His lawyer, James Ecker, said Kach was not forced to live with Hose.
Saparico's wife said she believes Kach had been brainwashed by her captor into staying with him.
Last year, Kach released her book Memoir of a Milk Carton Kid. In an interview before its release, she said that her mother had left home and she had a troubled relationship with her father. She befriended Hose, seeing him as an authority figure.
She said: "I was just so brainwashed. I feel humiliated now.
"About twice a week in the dead of night he led me down into a cellar with cold, concrete floors to take a shower. I was fine at first. I thought I was in love and felt my sacrifices were a labour of my love for Tom Hose. Soon, however, the ordeal began to take its toll.
"He's an absolute monster. There's just no words to explain him."
In the documentary, Kach recalls her 10-year captivity, saying she came "back from the dead" and is still rebuilding her life. The film features her estranged family, friends and police who worked on the investigation.
However, while many believe Kach's story, some have doubts over its authenticity, saying she instigated the disappearance and was never abducted by Hose.
Captive - the Sex Slave Girl: True Stories is on Channel 4 at 10pm tonight (Thursday)