SALT LAKE CITY -

FBI documents say investigators found child pornography on Josh Powell's computer at least 17 months before he killed his children and himself.

The Salt Lake Tribune reports that the documents show the FBI was investigating the disappearance of his wife, Susan Powell, as well as possession of child pornography.

Anne Bremner, an attorney for Susan Powell's parents, said the family was never told the FBI was investigating Josh Powell for child pornography. She said if the state of Washington's Department of Social and Health Services had known about the suspected child pornography, it "never would have let him have those kids."

Josh Powell ignited a fire that killed himself, 7-year-old Charlie and 5-year-old Braden at his rented home in Graham, Washington, on Feb. 5, 2012.