WATCHING the gruesome details of the Austrian incest case unfold, one question on many people’s minds is: “How could this be allowed to happen?”

An Austrian man who held his daughter captive for 24 years and fathered her seven children repeatedly warned his captives that they would be gassed if they tried to overpower him, investigators said today.

The Austrian dungeon ordeal children and their mother are inching towards normal life in a spacious hospital wing, doctors said today.

This week’s appalling discoveries in the Austrian town of Amstetten recall the case of Natascha Kampusch, the girl who spent eight years largely confined to an underground room in a Vienna suburb.

Austrian authorities say the case of the man who allegedly imprisoned his daughter for 24 years and fathered at least six children with her is one of the nation's worst-ever crimes.

An Austrian man has confessed to holding his daughter captive in a “house of horrors” for 24 years and fathering at least six of her children, police said today.