Sonar used to make sure no more underground dungeons exist 02/05/2008 00:00

Police used sonar technology to probe the yard of an Austrian man who held his daughter captive for 24 years in a secret dungeon.

2 May 2008

AMSTETTEN - Investigators were using sonar technology to probe the yard of an Austrian man who allegedly held daughter captive for 24 years to ensure that no more underground dungeons exist, police said Friday.

Leopold Etz, chief of homicide investigations for Lower Austria province, said investigators are also questioning more than 100 people who lived in Josef Fritzl's house over the years he is believed to have held his daughter Elisabeth prisoner in a secret dungeon, fathering seven of her children.

Police said the entire property is also being combed, including by officers using sonar to determine where there are any more secret rooms in the cellar.

''We're casting a wide net. ... It's a lot of work,'' Etz said.

Authorities said that what appears to have been an elaborate crime by Fritzl came to their attention 19 April when Elisabeth's eldest daughter, 19-year-old Kerstin, was admitted to a hospital suffering from an unidentified infection.

Baffled doctors appealed on TV for Kerstin's mother to come forward because they needed information about the girl's medical history. Fritzl then accompanied Elisabeth to the hospital 26 April, and her story came to light, authorities said.

Etz also said authorities were trying to verify whether a mechanism existed to pump gas into the dingy, windowless rooms where Elisabeth lived with Kerstin and two of her sons, as Fritzl claimed during police questioning.

Authorities have said the house had an official gas line, but for now they believe Fritzl's threat was nothing more than an attempt to keep his captives from trying to escape.

Police Col. Franz Polzer, who heads the criminal investigation, said investigators have determined that the entrance to the dungeon was protected by a reinforced double steel door that opened and closed using a remote control.

Investigators working in the underground rooms had to take frequent breaks due to a lack of oxygen, he said.

Former tenants have said Fritzl told all residents of the apartment house that the basement was off limits and they were not allowed to take photos in the area. Anyone who broke that verbal agreement was threatened with eviction.

Elisabeth's three other children by Fritzl - a son and two daughters - were removed from the cellar by him as babies, police said.

Fritzl and his wife, Rosemarie, who was told Elisabeth had abandoned the children, were granted custody over them. A seventh child died as an infant and Fritzl has confessed to burning its body in an incinerator, according to police.

Fritzl faces up to 15 years in prison if convicted on rape charges, the most grave of his alleged offenses. However, prosecutors said Tuesday they were investigating whether he can be charged with ''murder through failure to act'' in connection with the infant's death. That is punishable by up to 20 years in prison.

[AFP / ANP / Expatica]