For eight years, she was held captive, tortured and forced to slave for her psychopath kidnapper. Now, Austrian woman Natascha Kampusch is set to reveal the full extent of her ordeal in an autobiography due for release soon.

In March 1998, a 10-year-old Kampusch was picked up from a street by a man who bundled her into a car, drove her to his house and then locked her in a "hermetically-sealed" concrete dungeon, according to the Daily Mail.

The windowless cellar was equipped with only a pallet bed, toilet and sink.

What followed were 3096 days of physical torture and psychological trauma.

It was not before August 2006 that Kampusch, then 18, managed to escape and revealed to the world her horrifying experiences.

According to Kampusch, her captor – who identified himself to her as Wolfgang Priklopil - made her slave and slog, forcing her to shave off her hair and work semi-naked around his house. 'I always wanted to have a slave," Priklopil would tell her.

She writes of being beaten up to 200 times a week until her "spine snapped" and was ordered to address her captor as 'Maestro' or 'My Lord'.

"He'd grab me by the throat, drag me to the sink, push my head underwater and squeeze my windpipe until I almost lost consciousness," she told the Daily Mail.

So massive was her intrinsic struggle for survival that Kampusch says she began "regressing to the age of four or five" and began counting on her captor for physical intimacy and affection.

"I'd only have to do what the kidnapper asked and everything would be all right. Everything would proceed as it always did: the bedtime ritual, my mother's hand on my duvet, the goodnight kiss, the quiet tiptoe out of the room," she writes.

"I was not to be afraid, everything was going to be all right if I did what I was told. He looked at me like a child eyeing his new toy, full of anticipation and at the same time uncertain what to do with it".

Priklopil also told her that demands for ransom had been rejected by her family and that they were better off without her.

Some of her most graphic recollections include being manacled to Priklopil and sleeping with him in the same bed.

"It wasn't about sex. The man who'd beat me and locked me in the cellar had something else in mind: he simply wanted something to cuddle," she writes.

Kampusch also recollects how he never let her out of his sight, spying on her even when she bathed and accompanying her to the toilet.

"As the weeks went by, he dominated me more and more. I wasn't allowed to look him directly in the face. I had to ask permission if I wanted to stand up, sit down, turn my head or speak. He even accompanied me to the loo."

Kampusch found a chance to escape in 2006 while she was cleaning Priklopil's car.