Fritzl, 88, who was pictured for the first time in 15 years on Thursday morning while being driven to court, was reportedly close to tears on hearing the decision by a panel of three female judges at Krems regional court, in Austria.
He has been in a prison for “mentally abnormal” inmates since his conviction in 2009 for incest, rape, enslavement, coercion and the murder, by neglect, of his newborn son.
“He was a bit close to tears as he said once again that what he did was a terrible thing, and that he feels incredibly sorry for these people and that he wishes that he could undo it,” Ms Wagner said.
Despite suffering from dementia, the rapist was able to follow proceedings. It followed a psychiatric assessment that he no longer posed a threat of reoffending, according to reports.
From regular prison he can request to be released from prison altogether. Ms Wagner said she planned to submit such a request next year.
“His everyday life will remain similar. Prison is prison,” Ms Wagner said, adding that he would continue to receive psychotherapy.
In 2008, his daughter Elisabeth managed to tell police that he was holding her captive. As a 42-year-old, she said she had been held underground for 24 years and abused since the age of 11.
Fritzl lured her into the cellar, built in the style of a cold war bunker, when she was 18. He told his wife and family acquaintances that she had run away to join a cult.
Previously, he said he was “sure” his family would forgive him. In a rare statement issued through Ms Wagner, Fritzl told The Sun: “I miss my family very, very much. I am always thinking of them, and how I would like to see my grandchildren.
“But I definitely believe that I am going to see them again one day. I am sure that we are going to be reunited and I think they are going to forgive me for what I have done. I’m sure of it.”
Claiming to be “extremely sorry” and to “regret my crimes and the hurt I have caused”, Fritzl continued: “I would just add though, that I didn’t murder anyone or anything like that, so I do reject some of the ways I am sometimes referred to.”