Austrian police are investigating whether the unsolved killing of a young woman in 1986 is connected to a man who confessed this week to holding his daughter captive in his basement for 24 years and fathering her seven children.

The body of 17-year-old Martina Posch was discovered near a vacation property owned by Josef Fritzl's wife 10 days after the teen disappeared in 1986. Upper Austrian police Chief Alois Lissl said there were no concrete links in the case, but police are checking whether Fritzl had an alibi.

Posch's body is reportedly being exhumed so DNA tests can be conducted, according to freelance journalist David Hill, who named Fritzl as the main suspect in the unsolved case. Authorities did not confirm the report.

Meanwhile, more details have emerged about the three children taken from the basement cell in Amstetten, west of Vienna, where police say Elisabeth Fritzl was kept hostage and repeatedly raped since her disappearance in 1984 at age 18.

DNA test results released Tuesday confirmed that her father also fathered her seven children.

The three children kept in captivity, now aged 19, 18 and 5, had never left the tiny, cramped cellar where they were born, according to authorities.

"They've all got a very hunched-over posture from being kept in a very low-ceilinged room," Hill told CBC News on Wednesday.

"They're suffering from really a bad vitamin D deficiency, so they have an albino appearance — their hair is white, as is their skin."

Children said to have communication problems

Police who have been in contact with the children said they had trouble communicating, using "more like kind of an animal growling than actual words," Hill said.

Three other children born in the basement were raised by Fritzl, 73, and his wife Rosemarie, who according to police was unaware of her daughter's existence just one floor below. Another child died shortly after it was born.

Fritzl also admitted to having burned the baby's body, and said he locked his daughter in the cellar when she was 18, repeatedly had sex with her and fathered seven children, Franz Polzer, head of the criminal investigations unit in the province of Lower Austria, said Tuesday.

He faces up to 15 years in prison if convicted on rape charges. Prosecutors say they are investigating whether Fritzl can be charged with "murder through failure to act" in connection with the infant's death, which carries a maximum term of 20 years.

Elisabeth, now 42, reconnected Tuesday with her mother, who was told by Fritzl in 1984 that their daughter had run away to join a religious cult and later sent back three of her children to be raised by her parents.

Psychologists observing the emotional reunion concluded that Rosemarie was unaware her daughter was being held in captivity.

Two of the three children kept in captivity also reunited with their siblings Tuesday, while the third remained hospitalized. Officials said Elisabeth and her children are receiving psychiatric treatment.

The case came to light last week when Elisabeth's eldest child became ill and was taken to hospital by Fritzl. Having persuaded her father to let her meet doctors in her first trip outside the basement in 24 years, Elisabeth was finally able to reveal her ordeal to police and medical personnel.

With files from the Associated Press