The evil rapist is to undergo psychiatric tests to determine if he should be freed from jail where he has spent the last 15 years for keeping his own daughter as a sex slave.
The 86-year-old fathered seven children with his captive daughter Elisabeth who he raped repeatedly between 1984 and 2008 in a bunker under his home in Amstetten, Austria.
He was handed down a life sentence for his despicable crimes when he was jailed in 2009 but will soon be eligible to apply for early release.
If he walks free, he will have spent nine years less in captivity than Elisabeth when she was a prisoner of his basement dungeon.
Fritzl kept his daughter locked in a soundproof dungeon beneath the family home where he raped her more than 3,000 times.
While one child died shortly after birth, and was incinerated by the monster, three of the other kids were brought upstairs to live with him and his wife Rosemarie.
Fritzl told Rosemarie the children belonged to Elisabeth, and had been left on their doorstep as she was unable to care for them.
The three remaining children were kept in the windowless cellar – aged five to 19 when released – and would first see sunlight in 2008.
Fritzl’s crimes were uncovered when the oldest cellar child, a 19-year-old girl, became seriously ill.
Elisabeth begged her dad to take the girl, Kerstin, to hospital, but doctors quickly alerted cops after questioning the teen - who had never been in the outside world before.
In 2009, Fritzl was jailed for life after pleading guilty to murder by negligence over the death of the baby he cremated.
The other charges included enslavement, incest, rape, coercion and false imprisonment.
Elisabeth Fritzl has not had any contact with her father since he was jailed and lives under a new alias in an unknown part of Austria with the children conceived during the decades her own father brutally raped her.
The Regional Court of Krems in Lower Austria decided earlier this year that it would move Fritzl from a special unit for the criminally insane in Krems-Stein prison to the regular prison system.
This now makes him eligible to able to apply for early release, although the public prosecutor's office has immediately appealed the decision.