A 73-year-old Austrian man has confessed to holding his daughter captive in a cellar for 24 years.Police said on Sunday a 42-year-old woman told them her father, Josef Fritzl, lured her into the basement of the block where they lived in the town of Amstetten in 1984, and drugged and handcuffed her before imprisoning her.Franz Polzer, the head of the criminal investigations unit in the province of Lower Austria said: "He has now said that he locked up his daughter for 24 years, and that he alone fathered her seven children and that he locked them up in the cellar."Elisabeth Fritzl gave birth to seven children during her ordeal, one of whom died shortly after being born. Three had been kept locked up with their mother since birth and had never seen sunlight or received any education, police said.Police said Fritzl, a 73-year-old electrical engineering technician by training, was in custody and had told investigators how to enter the basement prison through a small hidden door, operated by a secret code which only he had known.Fritzl's wife Rosemarie had been unaware of what happened to her daughter and it was assumed Elisabeth had disappeared voluntarily when her parents received a letter from her a month after her saying they should not search for her.Authorities are still trying to piece together details of the case, which is reminiscent of that of Austrian Natascha Kampusch who spent eight years locked up in a windowless cell before dashing to freedom in August 2006.Three of Miss Fritzl's younger children were brought up by Fritzl and his wife after they were left at the building, the first child accompanied by a note from their daughter saying she was unable to care for the baby herself.Three others, including the two eldest aged 18 and 19, and the youngest, aged 5, had been locked up in the basement with their mother since birth.The case only came to light when the oldest child, a 19-year-old girl, became seriously ill and was 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.Mr Fritzl 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.Elisabeth agreed to make a "comprehensive statement" to police, after assurances that she would have no further contact with her father, who she said abused her from the age of 11.Mr Polzer said: "There is not only one, but a number of rooms: one room to sleep in, one to cook, and there are also sanitation facilities."The father seems to be very authoritarian and decided what happened and what was supposed to happen in the family - and today we know why he very closely guarded the basement," Mr Polzer said.Elisabeth, her children and her mother are receiving psychological counselling, and police said DNA samples of all those involved were taken for analysis.