Josef Fritzl could go on trial in December
Senior legal sources have revealed that he has admitted to sleeping with his daughter Elisabeth "two or three times a week" during the 24 years he kept her locked in a basement prison.
And Fritzl, 74, could be in court as early as December, Austrian media sources said on Monday.
Last week state prosecutors announced that Fritzl's trial would be heard in private apart from opening formalities and sentencing.
They expect to officially file formal charges by the end of October.
Austrian newspaper Kurier said court officials believed it might be impossible to find enough jurors who have not already made up their minds about Fritzl's guilt.
Under Austrian law there must be eight jurors and two substitutes.
"But we are a small country. There can't be 10 people out there who don't already have strong opinions about this man and what he's done," explained one legal source.
Fritzl kept daughter Elisabeth, 42, as his sex slave during 24 years of captivity, fathering seven children. One child died soon after birth.
Last week it was reported that Elisabeth Fritzl had rejected offers by Austrian authorities to give her family a new identity. She has said she will just change her surname.
Josef Fritzl: Incest dungeon father could face up to 3,000 counts of rape - Telegraph