A severely abused 42-year-old woman was held prisoner in a basement in eastern Austria by her father for 24 years, the dpa reported.
Police also suspect an extreme case of incest as the woman also has four children.
Police began searching for the woman when a 19-year-old girl, believed to be her daughter, was hospitalized in the town of Amstetten, Austrian state broadcaster ORF said.
Police believe she and her mother were held by her own grandfather in a basement dungeon and abused but declined any further comment. Investigations were continuing, police said.
Their plight was reminiscent of 19-year-old Natascha Kampusch, an Austrian girl who escaped her kidnapper after eight years in a basement dungeon in summer 2006.