12:01p.m. 12th November 2008

Monster: Josef Fritzl imprisoned and raped his daughter for 24 years. Photo:EuroPics

Josef Fritzl the Austrian who imprisoned his daughter and raped her repeatedly is living under the constant threat of rape and murder by fellow inmates.

The 74-year-old is being held in a Sankt Poelten prison - one of Austria's toughest - where he spends 23 hours per day in his cell watching TV and sleeping.

Prison guards allow him only two 30-minute exercise sessions per day under careful supervision because of the threat of violent reprisals by inmates who despise the incestuous rapist.

Prison staff have intercepted plans by inmates to sexually torture Fritzl before killing him. The inmates plan to rape him with toilet brushes before beating him to death.

Fritzl will be formally charged by Austrian police later this week.

He is accused of raping his daughter Elisabeth repeatedly for 24 years in a dungeon he specially built for the purpose in the basement of his family home in Amstetten, Austria.

Seven children were born out of the rapes. Three of them he selected to live with him upstairs, another three grew up with their mother in the basement and the seventh was burned in an incinerator when the boy died three days after his birth.

Fritzl's legal team will be seeking to prove that their client's mental state means he should be detained at a hospital, not a prison.

"He wouldn't last more than a few months in a real prison," said an adviser.

CEN