The basement of the Austrian house where Josef Fritzl imprisoned and repeatedly raped his daughter for 24 years will be filled up with concrete.

Walter Anzboeck, the liquidator of Fritzl's estate, says the move is to ensure the space can never be entered again.

Concrete will be pumped into the basement early next year, once town authorities in Amstetten issue a permit.

The 76-year-old Fritzl was sentenced to life in prison two years ago after being convicted of holding his daughter captive in a windowless cellar, fathering her seven children and for responsibility in the death of one of them.

No decision has yet been made about whether the house should be torn down.