Warren Jeffs is the imprisoned leader of the Fundamentalist Church of Jesus Christ of the Latter-Day Saints. He is serving a life sentence plus 20 years for the aggravated sexual assaults of a 12-year-old girl and a 15-year-old girl who he claimed were his “spiritual wives.”

Now two of Warren Jeffs’ adult children–Becky and Roy Jeffs–allege their father sexually abused them as children, too.

Becky and Roy Jeffs made their claims to Lisa Ling, host of CNN’s This is Life. The show airs on Wednesday night.

Two of Warren Jeffs Children Allege Sexual Assault: 'It Must be Something in His Nature" http://t.co/mNsN5MszmN pic.twitter.com/V7XOaapRPE

— People magazine (@people) September 30, 2015

Becky Jeffs admitted she first discussed being sexually molested by her father when her sister shared that she, too, had been molested by Warren Jeffs 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,” she 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?”

Despite being in prison, Warren Jeffs is still running the fundamental Mormon sect from behind bars. The group believes in polygamy and Jeffs is known to have fathered at least 60 children with some of his 78 wives.

What if your father was the "prophet," but did unthinkable things? Tonight on #ThisIsLife: http://t.co/c49F5caVqz https://t.co/1EK1Di1diH

— CNN Original Series (@CNNOriginals) September 30, 2015

The mainstream Mormon church–the Church of Jesus Christ of Latter Day Saints–renounced polygamy about 100 years ago.

CNN tried contacting Warren Jeffs via his attorney, but so far hasn’t received a reply.

What kind of excuses do you suppose Warren Jeffs might make regarding the alleged sexual abuse of Becky and Roy Jeffs?

Why do you suppose Warren Jeffs’ children waited so long to come forward?

They are only two of four of his children who have left the FLDS church.