Fritzl kept sex slave daughter chained up with a dog lead in the dungeon that SHE helped to build
Depraved Josef Fritzl kept his daughter chained to the wall by a dog lead during the first nine months of her imprisonment, it emerged today.
A chain was put around her neck and only released when she went to the toilet.
Documents leaked from police files also show that Elisabeth helped to build the prison where she was to spend the next 24 years of her life.
She had not been told what the cellar was for and had been ordered by her bullying father to help him work on it.
It was only when a 300 kilo door was put in place that she discovered she had built her own prison.
The leaked notes also show that Elisabeth lived the first nine years of her captivity in a single room where her children had to watch as she was repeatedly raped by her father.
It was only later that Fritzl, 73, had started to expand the cellar with additional rooms.
Until that point the children in the cellar had to watch while their mother was raped on "numerous occasions" - and even later when other rooms were added they still had to listen - as none of the rooms had doors.
Elisabeth told police her cellar ordeal started when she had been asked to help her father mount the steel and concrete entrance door, the final cellar component, and once this was completed he had drugged her and locked her up.
When she came to, she was handcuffed to a post and remained handcuffed for the next two days.
For the next six to nine months he had put her on a leash that kept her captive but allowed her to go to the toilet.
She reportedly told police he frequently came downstairs in that time to demand sex.
She said that at the start she had fought against the imprisonment, banging on the walls and screaming until she could no longer speak, but no one had come as the weeks turned into months, and the years into decades.
She said she had eventually stopped arguing with her father who in turn had stopped beating her as frequently.
Eventually she had become pregnant with Kerstin, now 19, and she had informed her father - fearing that he would be furious because he would now have to release her to go to hospital.
He had reportedly replied: "Do not think you are getting away from me so easily."
Details of the birth have not been spoken about by Elisabeth but afterwards Fritzl had continued to return frequently for more sex, at least once every three days.
After Kerstin there were further children, Stefan, 18, Lisa, 16 Monika, 15, Alexander, 12, whose twin brother died from neglect before he could even be given a name, and finally Felix, 5.
Elisabeth remained in the cellar until last month when her daughter who had reportedly suffered from epileptic attacks since birth, started once again to get severe cramps.
He agreed reluctantly to take Kerstin to hospital but only after chillingly making Elisabeth write a note to doctors.
Elisabeth was kept in one room of the dungeon, under the family home, for nine months
It read: "Wednesday, I gave her aspirin and cough medicine for the condition. Thursday, the cough worsened. Friday, the coughing gets even worse. She has been biting her lip as well as her tongue. Please, please help her! Kerstin is really terrified of other people, she was never in a hospital. If there are any problems please ask my father for help, he is the only person that she knows."
Elisabeth had to carry Kerstin, who weighed 50 kilos, upstairs to the car. It was the first time she had seen sunlight that reportedly temporarily blinded her.
As her eyesight slowly adjusted she noticed the way the house had changed, a swimming pool - and what seemed to be a conservatory and another garage had been added.
But just two minutes later she was back in the cellar and the door closed.
Kerstin's two brothers were reportedly both distressed at the sudden disappearance of their sister and had both asked where she was and what was happening to her "outside the door".
Records show the Fritzl then rang the emergency services saying: "This is an emergency, I have just found my niece unconscious."
On the 26 of April, Elisabeth was listening to the local television on the small TV she had in the cellar and saw a report from a doctor that she was being sought because the condition of her daughter had worsened.
For the first time in years she stood up to her father and demanded to be taken to the hospital - where she was found by police.
When Elisabeth spoke to police after she was rescued at the hospital on the 26 April, the information she gave was so shocking officers said they just sat and listened.
They described how she spoke fast, with long pauses as she seemed to struggle to gather her thoughts and look for the right words.
The interview lasted two hours, and produced notes that covered eight sides of A4 paper.
Elisabeth who is in a secure ward with her mother Rosemarie, 69, and five of her six children told investigators her father had acted alone in providing food and clothing for them.
Kerstin is still in an intensive care ward.