Apparently there was no limit to the depravity of Austrian Joesef Fritzl who kept his daughter in the cellar of his home for 24 long years and made her bear him seven children during that period.
He has now revealed in a newspaper interview he had fantasized about his mother too.
He has told London's Daily Mail
that he developed incestuous urges for his mother after she broke up with her husband.
He says: "My father was somebody who was a waster, he never took responsibility and was just a loser that always cheated on my mother. When I was four she quite rightly threw him out the house.
"After that, there was just us two. My mother was a strong woman, she taught me discipline and control and the values of hard work.
"When I say she was hard on me, she was only as hard as was necessary. She was the best woman in the world. I suppose you could describe me as her man, sort of. She was the boss at home and I was the only man in the house."
Asked by his lawyer if he had ever fantasised about a relationship with his mother, he pauses in the dialogue and thinks for a long time for answering.
"Yes, probably. But I was a very strong man, probably as strong as my mother, and as a result I was capable to keep my desires under control."
In comments related by his lawyer to weekly magazine News
, Fritzl, who locked up his daughter Elisabeth in 1984 when she was 18, said he started raping his daughter a year later.
"My drive to have sex with Elisabeth grew stronger and stronger," Fritzl was quoted as saying.
"I knew Elisabeth didn't want me to do what I did to her. I knew that I was hurting her ... It was like an addiction ... In reality, I wanted children with her."
Fritzl, who also has seven children through his wife Rosemarie, said he had locked up Elisabeth after she started to "break all the rules" following the onset of puberty.
She went to bars, drank alcohol and smoked and ran away a couple of times, the 73-year-old said.
"I tried to get her out of that swamp, organised her an apprenticeship to become a waitress.
"I needed to take precautions, I needed to create a place in which I could at some point keep her away from the outside world, by force if necessary."
Fritzl said he found himself trapped in an inescapable cycle once he had locked up Elisabeth. He told his wife their daughter had joined a sect, Reuters news agency reports.
"I knew all the time, during the whole 24 years, that what I did was not right, that I must be crazy to do something like that," he said, referring to Elisabeth's underground world as his "empire".
"But nonetheless, it became a matter of course for me to lead a second life in the basement of my house."
Fritzl's lawyer, Rudolf Mayer, has said his client should have psychiatric tests to evaluate whether he was fit to stand trial. Mayer said he might ask for a second assessment should the official court opinion not reflect his client's personality.
Fritzl described himself as a man who valued decency and good manners and said the emphasis on discipline in Nazi times, when he grew up, might have influenced him.
"Nonetheless, I am not the beast the media depicts me as.
"When I went into the bunker, I brought flowers for my daughter and books and toys for the children and I watched adventure videos with them while Elisabeth was cooking our favourite dish," he said.
"And then we all sat around the table and ate together."
Fritzl has been remanded in custody in the city of St Poelten. Mayer confirmed that Fritzl's comments were authentic.