AMSTETTEN, MAY 4: The wife of Austria’s accused “horror father” Josef Fritzl never believed her husband was involved in the 24-year disappearance of their daughter, even though he had already served an 18-month prison sentence for a 1967 rape conviction, her sister said.

In an exclusive television interview for The Associated Press, the sister-in-law of the man accused of imprisoning his daughter in a dingy dungeon for over two decades, repeatedly raping her and fathering her seven children has provided intimate details of a life of oppression inside the Fritzl home.

The woman, who asked only to be identified as Christine R. because she wants to avoid the wide attention the story has received, said incest victim Elisabeth ran away from home as a 17-year-old, about six months before police say she was locked into the soundproofed, windowless cellar beneath their apartment — hinting at a motive for the crime.

She described the father as a “tyrant” who instilled a culture of fear at home, which helped him create an elaborate cover story, which no one questioned, of Elisabeth running away to join a cult and abandoning three children on their doorstep in 1993, 1994 and 1997.

“When he said it was black, it was black, even when it was 10 times white,” said the woman, who was interviewed Saturday evening at her home in Austria. “He tolerated no dissent. Listen, if I myself was scared of him at a family party, and I did not feel confident to say anything in any form that could possibly offend him, then you can imagine how it must have been for a woman who spent so many years with him.”

If wife Rosemarie had challenged Fritzl, “we don’t know what he would have done to her. Maybe he would have slapped her,” the sister said. “In any case, he was a tyrant. What he said was good and the others had to shut up.”

“Every person that looked in his eyes was fooled by him,” Christine said of her brother-in-law. She said Rosemarie had no idea that her daughter was locked in the basement and did, for a while, frantically look for her elsewhere. The sister, 12 years her junior, remembered herself searching for Elisabeth in train stations and where homeless people hang out.

Christine R. said her sister devoted her life to her children — a task that she focused on with even greater effort after her husband was jailed. “I believe he spent a year and half in prison,” she said. She did not have more information on the rape conviction.

“My sister is apparently doing very badly and Elisabeth is not in the best shape either,” she said. “I know my sister and when something is wrong with her children the world collapses.... For sure, the world has collapsed for her.”