Austrian Josef Fritzl said he became addicted to incest with his daughter, who bore him seven children, and had imprisoned her in a cellar to save her from the outside world.
But in comments published Thursday, Fritzl said he tried to care for her and their children by bringing them flowers, toys and books.
"I constantly knew, during the entire 24 years, that what I did was not right, that I must have been crazy because I did something like this," the Austrian magazine News quoted Fritzl as saying through his lawyer.
The lawyer, Rudolf Mayer, confirmed Thursday to The Associated Press that Fritzl made the remarks during a series of conversations with him at a prison in St. Poelten, west of Vienna, where he is being held in pretrial detention.
Since the case came to light last month, Fritzl has confessed to locking up daughter Elisabeth, 42, in 1984, repeatedly raping her and fathering her seven children. He said three of the children were raised in a cellar in his home in Amstetten, never seeing the light of day; three were raised above ground by him and his wife, and one died in infancy.
Charges have not yet been filed against him.
Fritzl said he started raping his daughter in 1985 when she was aged 19. Elisabeth has told police that Josef started sexually abusing her when she was 11.
'I knew I was hurting her'
"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 with 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, organized 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."
Nazi discipline
Fritzl said he found himself trapped in a inescapable cycle once he had locked up Elisabeth. He told his wife their daughter had joined a sect.
He referred to Elisabeth's underground world as his "empire" and described himself as a man who valued decency and good manners. He 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 favorite dish," he said.
"And then we all sat around the table and ate together."
Fritzl's double life began to disintegrate when Elisabeth's oldest child, a 19-year-old woman, was hospitalized with a severe infection.
Unable to find medical records for the woman, doctors appealed for her mother to come forward. Fritzl accompanied Elisabeth to the hospital on April 26.
'Only man in the house'
In other comments published by the News, Fritzl said he grew up an only child in "humble circumstances" and that his mother, whom he "admired very much," threw his father out of the house when he was 4.
"She was the boss at home, and I the only man in the house," Fritzl said of his mother.
Fritzl, who always wanted to have a large family, said he was happy about the children Elisabeth bore him. To prepare her for labor, he brought her medical books, towels, disinfectants and diapers, he said.
"Elisabeth was, of course, scared of the delivery," he said.