(CNN) -- Polygamist leader Warren Jeffs is once again running the Fundamentalist Church of Jesus Christ of Latter Day Saints -- this time from a jail cell, sources tell CNN.

Jeffs gave up control of the splinter sect that advocates plural marriages, including marriages that involve girls under 18, after he was convicted in 2007 of rape as accomplice. That conviction was overturned last year. Jeffs is currently awaiting trial in Texas on sexual assault and bigamy charges.

Sources within the church tell CNN that the man who replaced Jeffs as business head of the church, Wendell Nielsen, has resigned and that Jeffs has signed documents retaking control of FLDS.

The FLDS splintered from the Mormon Church more than a century ago when Mormons renounced the practice of polygamy. Jeffs' church is believed to have about 10,000 followers.

Critics of the FLDS say underage girls are forced into "spiritual" plural marriages with older men and are sexually abused. Sect members have denied sexual abuse.

Texas prosecutors filed charges against Jeffs in 2008 after authorities raided the sect's Yearning for Zion Ranch in El Dorado, Texas. They removed 400 children whom authorities feared had been sexually abused. While some of the men at the ranch were charged with sexual abuse, most of the children were later returned to their families.

Jeffs was eventually extradited from Utah to Texas. He was arraigned on the Texas charges in December in Tom Green County. Jeffs is scheduled to go to trial later this year.

Gary Tuchman contributed to this report.