An expert is set to decide if Austrian basement dungeon mastermind Joseph Fritz, who fathered seven children with his captive daughter, should walk free.

Fritzl is currently serving a life sentence, but he will soon be eligible to apply for early release, having served 15 years for his crimes.

If he is allowed to walk free, he will have spent nine years less in captivity than his daughter when she was a prisoner of his basement dungeon.

In autumn, the Regional Court of Krems in Lower Austria decided that it would move Fritzl from the prison system for mentally abnormal lawbreakers to the regular prison system.

This, in turn, would mean that after having served 15 years of his sentence, he would be able to apply for early release.

But the public prosecutor’s office was opposed to this plan and immediately appealed the decision.

Now, the Higher Regional Court has taken over the case and appointed an expert to examine the inmate in a bid to determine his psychiatric and neurological condition.

If the expert detects any abnormalities, Fritzl will have to remain in the prison system and will not be eligible to ask for early release.

But if the expert deems that he is of sound mind, then the Austrian, who was jailed for keeping his daughter Elisabeth in a basement dungeon that he built himself and managed to keep a secret for years while he raped her and fathered seven children with her, could be released from prison.

The expert opinion is expected by the end of January.