2 of Warren Jeffs’ children say he sexually abused them — VIDEO

For the first time, two children of Warren Jeffs have alleged that the imprisoned leader of the polygamous Mormon sect sexually abused them as children.

Becky and Roy Jeffs, both adults, made the revelations to Lisa Ling on her upcoming CNN show "This is Life," which premieres Wednesday night. They both recently left the Fundamentalist Church of Jesus Christ of the Latter-Day Saints, or FLDS.

Becky told Ling that she first told one of her sisters, after her sister revealed she was abused as a child.

"I thought, I'm not the only one molested, he's done it to her it must be something that was in his nature," Becky Jeffs says on the show. "Where does it end? If he had this in him, how can I trust him? How is he really our prophet?"

CNN reached out to Warren Jeffs' attorney who did not have an immediate response from his client.

Becky and Roy are among four of Jeffs' children who have left the FLDS, which is based in the twin cities of Colorado City, Arizona, and Hildale, Utah, where recent floods devastated the community.

Warren Jeffs fathered some 60 children with some of his estimated 78 wives. The elder Jeffs is serving a life sentence, plus 20 years, after he was convicted in 2011 of the aggravated sexual assaults of a 12-year-old girl and a 15-year-old girl who Jeffs claimed were his "spiritual wives."

Despite his imprisonment, Jeffs is still firmly in control of the 10,000-member Fundamentalist Church of Jesus Christ of Latter-Day Saints. The FLDS is a breakaway Mormon sect that openly practices polygamy, something the mainstream Mormon church renounced more than a century ago.