Josef Fritzl has pleaded guilty to incest and rape after locking his daughter in a cellar for 24 years, but has denied charges of murder and enslavement.
As his trial opened in Austria, Josef Fritzl again denied murdering a newborn boy. He had previously told police the baby was still-born and he burned the body in a boiler in the cellar.
He has also pleaded not guilty to a charge of enslaving his daughter Elisabeth for most of her life.
The story of Josef Fritzl came to light in the spring of last year.
The 73-year-old locked up his daughter in a purpose built dungeon in August 1984, and kept her prisoner there for 24 years.
He raped her repeatedly, fathering seven children, one of whom died shortly after birth.
Josef Fritzl told the outside world that Elisabeth had joined a religious cult, only to deposit unwanted babies on his doorstep.
He brought these children upstairs into the family home in the Austrian town of Amstetten.
His crimes came to light last year when Elisabeth's eldest daughter had to be hospitalised.
He faces a panel of three judges and a jury of eight people.
As he entered court this morning amid tight security, he attempted to hide his face from the cameras.
Elisabeth, now aged 43, and her children have provided some 13 hours of video testimony.
The murder charge carries a life sentence while the other charges of incest, rape and coercion carry a maximum sentence of 15 years.
