Austrian authorities have arrested an elderly man accused of imprisoning and sexually abusing his daughters in their home for four decades.

Police said Thursday the man has denied the accusations of his mentally disabled daughters, aged 53 and 45. They have accused him of confining them in one small room, repeatedly raping and beating them, and threatening to kill them if they tried to escape.

Local reports say the sisters escaped the house in May after the older sister pushed her father to the ground, where he lay unable to get up. A social worker found him two days later, and he was placed in a senior adults' home.

It is unclear why the story did not emerge until Thursday. Names of the suspect and victims were not released.

The case is reminiscent of that of Josef Fritzl, an Austrian man who was sentenced to life in prison in 2009 after being found guilty of keeping his daughter locked up in a cellar for 24 years and fathering her seven children. Fritzl also was convicted of murder for the death of his daughter's infant son, who was not given medical care after becoming ill.