Missing Utah mother Susan Powell's father Chuck Cox said the child pornography charges filed against her father-in-law make it clear that Steven Powell's claims that the young woman was "very sexual" with him were lies.
"I do think it vindicates my daughter, and what we've said about her and it clearly shows that he had motive to detract from her reputation," Cox said today on "Good Morning America."
Susan Powell's husband, Josh Powell, is the lone person of interest in the woman's December 2009 disappearance, and the case has created a bitter rift between the two families.
Cox's statements today come as it was announced that Susan Powell's two sons are in foster care this morning after their grandfather, Steven Powell, was arraigned Friday on child pornography charges. He entered a plea of not guilty.
Josh Powell and the couple's two children had been living with Steven Powell for several months.
"I am hoping they will keep my nephews out of that house," Susan Powell's sister, Denise Cox, said Friday outside the arraignment hearing.
Steven Powell, 61, is charged with using a telephoto lens to take photos of two girls, age 8 and 10, in the bathroom of a neighboring house.
The photos are among thousands he is accused of secretly taking, including shots of women's buttocks and breasts, that police found in his home, according to the charges filed against him.
Powell, who arrived in court in an orange jumpsuit for his first appearance before a judge, is being held on $200,000 bail.
Susan Powellwas among the females photographed, prosecutors said.
"There are photos of girls in bathtubs and showers, using the toilet, taking baths," said Ed Troyer, a police officer at the Pierce County, Wash., Sheriff's Department.
Powell was arrested Thursday night by Pierce County sheriff's officers on 14 counts of voyeurism and one count of possessing child pornography after police raided his home in August and found thousands of images and videos of women and girls.
Prosecutors told a judge Friday that the charges represent just the beginning of what was found in the files taken from the home, and that Powell had been taking photos and videos for at least 10 years.
Steven's estranged daughter Jennifer Graves said she was not surprised by the disturbing discovery.
"I think it's despicable. I've known for a long time that my Dad had issues. Now we're learning Josh Powell is not the only person of interest in his wife's disappearance ... though police will not say who that other person is," Graves said.
Susan's family has said Steven Powell initiated unwanted sexual advances towards her. But in a recent interview with ABC News, Steven Powell denied any wrongdoing.
When asked if he had anything to do with Susan's disappearance, he said, "I had nothing to do with it."
Steven Powell claimed that he and his daughter-in-law had a relationship that was "beyond the pale, you know, father-in-law, daughter-in-law, flirting, maybe some sexual touching or whatever."
"Susan was very sexual with me," he said. We interacted in a lot of sexual ways because Susan enjoys doing that."
Steven Powell said he had started falling love with his daughter-in-law and that the feelings were mutual.
"Really, I'm 30 years older than she is," he said. "I said, 'Well Josh, it was Susan that came on to me.' As he thought about it, and the next few months he started watching Susan more carefully, it became clear that that's how she interacted with the opposite sex."
Josh Powell denied any type of sexual relationship between his father and his wife, but admitted that his wife was a very sexual person.
Investigators wrapped up a 12-day search of the Utah desert Friday, not far from where Josh Powell says he took the couple's two sons on a midnight camping trip in December 2009, the night before Susan was reported missing.
Denise Cox said she thinks Steven Powell is hiding something.
When asked by a reporter if she believes Steven Powell had anything to do with her sister's disappearance, she said, "Yes, yes I do."
Another hearing on the custody of the Powell boys is scheduled for Wednesday.