Fritzl said he had never intended to rape Elisabeth, now 42, but felt an "overpowering" desire for "a taste of the forbidden". He added that he raped her while thinking of his own "lonely" childhood and said he "wanted them (the other children) to always have someone to play with".
After complaining that he had been unfairly portrayed as a monster by the media, he was asked how he would describe someone who had committed the horrific acts that he had.
"On the face of it, probably as a monster," he replied, but insisted he did not have sex with Elisabeth until she was much older than 12, which is when she claims he first abused her.
"I am not a man that has sex with little children. I only had sex with her later, much later. It was when she was in the cellar by then, when she had been in the cellar for a long time.
"My desire to have sex with Elisabeth also got much stronger as time went by. We first had sex in spring 1985. I could not control myself any more. At some stage somewhere in the night I went into the cellar and laid her down on the bed and had sex with her."
He said his daughter, then 19, had cried, but that did not stop him. "I knew that Elisabeth did not want it, what I did with her. The pressure to do the forbidden thing was just too big to withstand."
Fritzl would visit Elisabeth every few days, delivering food and clothing and repeatedly raping her.
"It was an obsession with me," he said, adding that Elisabeth had fallen pregnant for the first time in 1988, giving birth to Kerstin, then a year later to Stefan.
"Elisabeth was of course very worried about the future, but I bought her medical books in the cellar, so that she would know when the day came what she had to do, and I arranged towels and disinfectants and nappies."
"I was delighted about the children. It was great for me to have a second proper family in the cellar, with a wife, and a few children. We celebrated birthdays and Christmas in the cellar, I even bought a Christmas tree secretly into the cellar and cakes and presents."
