Austrian police are now convinced that Josef Fritzl had been planning to imprison and rape his daughter well ahead of time, prompting them to investigate the years of Fritzl's life that preceded the crime, the head of police Franz Polzer told a news conference in Amstetten today.
"He's been planning to build the secret dungeon in the early '80s -- years before he eventually abducted his daughter Elisabeth -- which indicates to us he's been planning his evil crime meticulously for quite some time," Polzer said.
Polzer also said that his investigators "have been able to find another secret door, allowing for a hidden access to the dungeon. This door was hidden behind a heavy metal door, which leads to a soundproof gateway to the electronically secured door, which they had first discovered when they entered the basement prison nine days ago."
Prosecutor Gerhard Sedlacek today revealed that Elisabeth Fritzl had returned with investigators to the windowless dungeon, which was her home for almost 24 years, to help them with their work.
The small Austrian town of Amstetten has become an attraction for so-called catastrophe tourists looking to get a first-hand glimpse of the "house of horrors" where an incestuous father admittedly imprisoned and raped his daughter, fathering seven of her children.
The scandal deepened as more details came to light this weekend.
For the first time, a relative of Fritzl's family has come forward to speak publicly about the man and his secrets.
Christine R., Fritzl's sister-in-law, said in a video interview, which aired on several Austrian TV channels, that he was convicted of rape about the same time that Elisabeth was born.
He served 18 months in jail for the offense in 1967, while his wife, Rosemarie, tried to keep her young family together.
Christine, whose last name was not revealed, said the man was a tyrant who ruled his house like a military dictator.
"He tolerated no dissent," she said in the interview. "Josef Fritzl, who was known as 'Sepp,' scared everybody in the family. I was scared myself. I never felt confident to say anything that could possibly offend him."
"Sepp had a regular routine," she said. "He would go into the cellar in the morning and spend all day down there, and often he would spend the night. Questions about why he was down there for so long were banned. My sister Rosemarie was not even allowed to bring him a cup of coffee. Rosie and the kids lived in complete fear of him."
Christine said the man treated his children like soldiers under his command. Everybody had to be silent when he entered the room.
Meanwhile, Polzer told reporters how Elisabeth Fritzl, 42, was kept in a single, narrow room on an extended cable, resembling a dog leash, for the first nine months of her imprisonment. The cable extended just far enough for her to get to the toilet but otherwise restricted her movement to a minimum.
"She [Elisabeth] said there was only one single room, which was expanded by Fritzl only after the first four children were born," the head of police said
Investigators in Amstetten are reportedly convinced that the children -- who were trapped in the cellar with Elisabeth -- must have witnessed Fritzl sexually abusing their mother and that he threatened them that they would be gassed if they ever tried to escape.