A woman last night claimed she was held prisoner in a cellar for almost 24 years by her father, who repeatedly raped her and fathered at least six children.

A woman last night claimed she was held prisoner in a cellar for almost 24 years by her father, who repeatedly raped her and fathered at least six children.

Austrian police said the 42-year-old woman, identified as Elisabeth F, had been missing since August 29, 1984, and three of her children had been trapped with her since birth. She was found by police in Amstetten on Saturday night following a tip-off.

Franz Polzer, head of the Lower Austrian Bureau of Criminal Affairs, said the 73-year-old father, identified as Josef F, had been taken into custody.

In a chronology of events outlined in a statement, police said a letter written by Elisabeth F had apparently surfaced a month after her disappearance asking her parents not to search for her.

Police said that, during questioning, Elisabeth F alleged her father began sexually abusing her when she was 11. She claimed he sedated, handcuffed and locked her in a room in the cellar on August 28, 1984, in the Lower Austrian town of Amstetten.

During the 24 years that followed, she said she was continually abused by her father and gave birth to six children, according to the statement.

In 1996, she told police that she gave birth to twins but one died several days later because it was not appropriately cared for. Josef F had then allegedly removed the corpse from the cellar and burned it.

It was not immediately clear if the twin who died was included in the police tally of the number of children.

Yesterday's developments are reminiscent of the case of Natascha Kampusch, which shocked Austrians less than two years ago. Ms Kampusch was 10 years old when she was kidnapped in March 1998 and was held for eight-and-a-half years by Wolfgang Priklopil. Last night police said investigators found the area in a cellar where the woman had been held captive along with three of her children.

Mr Polzer said the area had a "very narrow" hallway and "a number of rooms: one room to sleep in, one to cook, and there are also sanitation facilities".

Police found it after Josef F gave them a code to unlock a hidden door, he added. "Everything is very, very narrow and the victim told us this was continually enlarged over the years," Mr Polzer said.

Elisabeth F said she and her children got food and clothing from the father only, and her mother had not been involved.

Police picked up Elisabeth and her father on Saturday night close to the Amstetten hospital after they received a tip-off.

The case only came to light when the oldest child, Kerstin F, became seriously ill and was taken to hospital in Amstetten. Josef said that child had been left unconscious on his doorstep.

The 19-year-old girl, who was seriously ill and is still fighting for her life, was last weekend dropped off at the hospital in Amstetten.

Doctors appealed for the girl's mother, who at that time was believed to have disappeared, to come forward to provide more details about the daughter's medical history. Josef then brought Elisabeth and her remaining two children out of the dungeon, telling his wife that their "missing" daughter had chosen to return home, police said.

Police said Elisabeth F appeared "greatly disturbed" psychologically during questioning.

Police said three of the children were registered with authorities and lived with the grandparents.

Josef F and his wife had told authorities they had found those children outside their home in 1993, 1994 and 1997, each time with a note from the mother. In the first letter, Elisabeth F had apparently said she already had a daughter and son. In another letter, she said she gave birth to another son in December 2002.

Josef F has been arrested, but has not admitted any crime.

DNA tests are expected to determine whether Josef F is the father of the children.