Austrians describe the pale grey, two-storey family home near the centre of this provincial town as the "house of horror". It is not difficult to understand why. In its cramped cellar, 73-year-old Josef Fritzl held his own daughter prisoner, beat her and raped her, fathering seven children with her over a period that lasted nearly a quarter of a century.
Two of Fritzl's sons, aged 18 and five, were freed from lifelong imprisonment in his cellar at the weekend. Yesterday, the back entrance of the house containing the cellar prison was surrounded by police entry tape and dozens of TV camera crews.
Hours earlier, Fritzl made a full confession about his crimes, which investigators described as the "worst and most shocking case of incest in Austrian criminal history". The retired electrical engineer, who has seven other children with his own wife, was due to be charged last night.
Police in Amstetten revealed the details of the case yesterday which they said had come to light after protracted questioning of Fritzl and his daughter Elisabeth, 42, who was first sexually abused by her father at the age of 11. She gave birth to seven children during her ordeal.
Elisabeth Fritzl's nightmare began in earnest at the age of 18 in 1984. Police said her father drugged and handcuffed her and then imprisoned in his cellar behind a steel door concealed in a narrow corridor.
It was there that Fritzl subjected his daughter to a seemingly endless horror story involving incest, beatings and continuous rape. Police revealed that Elisabeth bore seven children as a result of being raped. Three were sent upstairs where they were "adopted" by Fritzl and his wife Rosemarie, who professed to knowing nothing about her husband's incestuous relationship with her daughter.
One of the three other children who were kept in the cellar died there less than a year after being born. Police said Fritzl got rid of the evidence by throwing the corpse into a furnace. All of the children were born in the dungeon without medical supervision. "Elisabeth Fritzl had to cope completely on her own," said a police spokesman. Fritzl apparently bought them a few clothes.
Police photographs of Elisabeth Fritzl's cellar prison revealed the existence of several tiny underground chambers, a washing space and a cooking area. Police said the underground complex, measuring 80sq m, also contained a rubber-walled "padded cell" and that childish drawings of animals and a sun had been painted on walls. The only concession regarding the outside world appears to have been a television.
Franz Polzer, the head of Lower Austria's police criminal investigation department, said Fritzl had deliberately manufactured a series of elaborate lies to conceal his crimes from police, his own children, neighbours and even his own wife. "If you look at him today, you would hardly believe he was capable of doing these things. This man led a double life for 24 years," he said.
Fritzl managed to convince police his daughter had gone missing shortly after he abducted and imprisoned her in 1984. He was said to have coerced his daughter into writing a letter in which she claimed she was unable to cope with her life and had run off to join an obscure religious sect.
The Austrian authorities appear to have been convinced by Fritzl's lies and gave up looking for her shortly after her disappearance in 1984.
Three of the children fathered by Fritzl – two daughters aged 15 and 14 and a son aged 12 – were allowed to live "normal" lives above the cellar. However Elisabeth remained imprisoned in the cellar with her oldest daughter, Kerstin 19, and two of her other sons, aged 18 and five, the whole time.
Police first suspected foul play on 19 April after Kerstin Fritzl turned up at an Amstetten clinic. Doctors said she was seriously ill and fighting for her life with an undisclosed illness. Doctors appealed on television for Elisabeth Fritzl to come forward and help her daughter. "Josef Fritzl then for once showed he had a human side and allowed his daughter [Elisabeth] out of the cellar to join his daughter [Kerstin]," said Mr Polzer.
Once she reached hospital Elisabeth Fritzl supplied police with a statement explaining her 24-year ordeal. Fritzl was arrested shortly afterwards and later confessed to his crimes and said he regretted his behaviour. However he did not make a full confession until yesterday.
Neighbours in Amstetten's Ybbsstrasse, where the Fritzl house is located, reacted with disbelief yesterday. Maria, an elderly woman, said: "I just don't believe it. They were nice people. I used to watch them taking their three children to school." Classmates of Fritzl's three "normal" children who lived upstairs told Austrian Radio: "The Fritzl girls and the boy always kept a bit apart in school. They kept away from the others and seem to lead separate lives."
The Amstetten scandal is certain to raise further questions about the conduct of Austrian police in cases involving missing persons. Above all, why police, social services, doctors and teachers at the schools attended by the Fritzl children failed to detect than anything was amiss for nearly a quarter of a century.