A woman who went missing in 1984 was found by police over the weekend and told investigators that she had been held by her father in a cellar, where she was repeatedly raped and gave birth to at least six children, police said Sunday.
Authorities said that the father may have told acquaintances and relatives that his daughter had joined a cult and disappeared.
Franz Polzer, head of the Lower Austrian Bureau of Criminal Affairs, told reporters that the father, identified as Josef F., had been taken into custody. Police said Josef and his wife had been raising three of their daughter's children. The other three grew up in the cellar, AP reported.
"We are being confronted with an unfathomable crime," Interior Minister Guenther Platter said.
The case unfolded after a gravely ill teenager was found unconscious on April 19 in the building where her grandparents live, and taken to a hospital in the town of Amstetten. Told that the sick 19-year-old's mother was missing, authorities publicly appealed for her to come forward.
Officers received a tip and picked up the mother near the hospital on Saturday, police said.
The mother, whom authorities identified as Elisabeth F., told officers that she had just been released after two decades of captivity at the hands of her father. She said that on Aug. 28, 1984 her father had sedated her, handcuffed her and locked her in a room in the cellar of the family's apartment building.
In an interview with AP Television News, Polzer said that Josef F. had given police a code to unlock a hidden door, revealing the area where Elisabeth and the children had been held.
It had several rooms, an uneven floor and a very narrow hallway, Polzer said, adding that the door was very small, and that one had to bend one's head to get through.
"Everything is very, very narrow and the victim herself ... told us that this was being continually enlarged over the years," Polzer said.
The area also contained sanitary facilities and small hot plates for cooking, Polzer said.
On its Web site, ORF reported that the rooms were at most 5.6 feet high and that the area had a TV.
The area also included a "padded cell," Hans-Heinz Lenze, a senior Amstetten district official, said in remarks broadcast late Sunday.
Elisabeth said her father had been sexually abusing her since she was 11. According to the police statement, Elisabeth said that she and her children got food and clothing only from her father and her mother, Rosemarie, had not been involved.
Police said Elisabeth F. appeared "greatly disturbed" during questioning and agreed to talk only after authorities assured her she would no longer have to have contact with her father and that her children would be cared for.
Police said Josef, 73, and Rosemarie had raised three of Elisabeth's children in their apartment in a two-story building in Amstetten, a small town about 80 miles west of Vienna.
Josef and Rosemarie registered the children with authorities, saying that they had found them outside their home in 1993, 1994 and 1997, at least one with a note from Elisabeth saying she could not care for the child.
The three other children apparently remained in the cellar with Elisabeth, police said.
"Elisabeth F. taught them how to speak," Polzer was quoted as saying by the Austria Press Agency.
Police said the sick 19-year-old, Kerstin, had been found unconscious on April 19 in the apartment building, with a handwritten note purportedly signed by Elisabeth, asking that she be given care.
After Kerstin was hospitalized, police said, Josef F. freed Elisabeth and the two remaining children from the cellar and told his wife that their daughter and the children had come back to them.
The Austria Press Agency reported that, in addition to Kerstin, three of the children are boys and two are girls, the youngest of whom is 5.
All are in psychiatric care, along with Elisabeth and Rosemarie, police said. DNA tests are expected to determine whether Josef F. is the father.
Police cited Elisabeth as saying that she gave birth to twins in 1996 but one died several days later because it was not properly cared for, according to police, who said they are investigating.
Josef, the alleged abuser, then apparently removed the corpse from the cellar and burned it, the police statement said. It was not immediately clear if the twin who allegedly died was included in the police total of six children.
Sunday's developments are reminiscent of the case of Natascha Kampusch, which shocked Austrians less than two years ago.
Kampusch was 10 years old when she was kidnapped in Vienna on her way to school in March 1998. She was held for the next 8 1/2 years by Wolfgang Priklopil, who largely confined her to a tiny underground dungeon in his home in a quiet Vienna suburb. Priklopil threw himself in front of a train just hours after Kampusch's dramatic escape on Aug. 23, 2006.