Steven Powell, father-in-law of missing Utah mother, arrested on child porn charges (VIDEO)

An investigation into the 2009 disappearance of Utah mother Susan Powell-Cox has taken a bizarre turn, with the arrest of Powell-Cox's father-in-law on child pornography charges.

Steven Powell, 61, was taken into custody Friday, less than a month after investigators from Pierce County, Washington, and West Valley City, Utah, searched his home and found videotapings and pictures of young girls and women, filmed without their knowledge, including some of his daughter-in-law.

Powell has pleaded not guilty to charges of using a telephoto lens to take photos of two girls, age 8 and 10, in the bathroom of a neighboring house, ABC News reports.

The videos were found in Steven Powell's bedroom, Prosecutor Mark Lindquist said in a statement, the Daily Mail reports. "The photographer focuses on the women's buttocks, breasts. Many images were of minor females."

Powell was charged with 14 counts of voyeurism involving two child victims, and one count of possessing child pornography, ABC News reports.

Powell-Cox's sons, ages four and six, who had been living at their paternal grandfather's home along with their father, Josh Powell — the sole person of interest in Powell-Cox's disappearance — are now in foster care.

The judge at Steven Powell's arraignment reportedly ordered him not to have contact with his grandsons, the Daily Mail reports, and set bail at $200,000.

Steven and Josh Powell had been locked in a bitter custody battle with Powell-Cox's father, Chuck Cox, for the Powell-Cox's two sons.

Steven's estranged daughter Jennifer Graves has told ABC that 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."

Cox, meantime, has said that the discovery of child pornography at the house made it clear that his 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 reportedly said on Good Morning America.

Steven Powell had told ABC's Good Morning America that he had a flirtatious relationship with his daughter-in-law and believed they were in love.

"Susan was very sexual with me. We interacted in a lot of sexual ways because Susan enjoys doing that."

Cox, Susan's father, denied the allegations, and said it was Steven Powell who initiated unwanted sexual advances.

After the arraignment hearing Friday, he reportedly said: "We're very concerned for the welfare of our grandchildren. We're doing everything we can."

Susan Powell-Cox's sister, Denise Cox, also outside the hearing Friday, said: "I am hoping they will keep my nephews out of that house."

Utah police, meantime, are still searching a remote stretch of desert near where Josh Powell says he went camping the night his wife vanished.

Police have reportedly said he has been uncooperative in their investigation.

But Powell has denied killing his wife. "I would never even hurt her," he told CBS' Early Show in August, in a tearful interview.