Two children of now-imprisoned Mormon sect head, Warren Jeffs, have spoken up about the alleged sexual abuse they experienced during their childhood.

The story of Becky and Roy Jeffs were revealed on the show "This is Life" which will start airing on Wednesday. The siblings just left the Fundamentalist Church of Jesus Christ of the Latter-Day Saints, commonly known as FLDS, CNN reported.

The daughter only revealed the details of the abuse only after knowing that one of her sisters suffered the same thing from Jeffs.

"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 said, according to CNN. "Where does it end? If he had this in him, how can I trust him? How is he really our prophet?"

The son also remembers how his father did the same thing to him.

"I was about four or five-years-old and this is where my dad did it," Roy Jeffs said as he was pointing at a house in some scenes of the show, International Business Times reported. "I remember him telling me, 'You should never do this.' And then he did it to me."

The siblings are only two of the four children of Jeffs that left the enclaves of FLDS located in Colorado City, Utah and Hildale, Ariz. An estimated 60 children have been fathered by Jeffs through his 78 wives, People reported.

Jeffs was convicted in 2011 for the crime of aggravated sexual assault of one pre-teen girl and another teenage girl.