LAS VEGAS — The "mother lode" of evidence the FBI seized when it arrested Fundamentalist LDS Church leader Warren Jeffs will be fought over in a federal courtroom today.

A hearing is scheduled on who can get involved in the fight over papers, ledgers, letters, computers and other items that were found in the Cadillac Escalade in which Jeffs was riding. Among those who want a peek: the court-appointed special fiduciary of the United Effort Plan Trust, an ex-FLDS Church member who won a lawsuit against Jeffs, and the Utah Attorney General's Office.

The feds don't seem willing to give it up.

"We will just continue with our same interest in the case," said Melodie Rydalch, a spokeswoman for the U.S. Attorney for Utah, which is handling the case. "That is protecting the evidence that can be used in a criminal case."

Lawyers for the man placed in charge of the FLDS Church's financial empire want to see if any of the evidence tells them anything about the UEP Trust.

"It could tell a lot," said Jeffrey L. Shields, an attorney for court-appointed special fiduciary Bruce Wisan. "We're hopeful it will give us some insight into the previous management of the trust."

In 2005, a judge in Salt Lake City's 3rd District Court took control of the trust after allegations surfaced that Jeffs and other top FLDS leaders had been "fleecing" the $110 million financial empire of the polygamous church. The UEP Trust was recently reformed, doing away with the "united order" and paving the way for private property ownership.

Wisan has been told that the documents are the "mother lode" of information about the polygamous church's inner workings and business interests.

FBI agents have told the Deseret Morning News the seized evidence includes ledgers containing names of people who helped keep Jeffs on the run. The FLDS leader was put on the FBI's Ten Most Wanted list until he was arrested in a traffic stop outside Las Vegas in August 2006.

Shortly afterward, his lawyer Richard Wright filed an emergency motion in federal court demanding the return of the documents, saying they are "privileged communications" between the FLDS leader and his followers.

"The administrative impound impinges on the First Amendment right to the free exercise of religion insomuch as the government took possession of religious documents which are deemed confidential and sacred by the FLDS," Wright said in his motion.

Shields fought to see what the FBI seized when it arrested Jeffs' brother, Seth, during a traffic stop in Pueblo, Colo., last year. Seth Jeffs later pleaded guilty to harboring a fugitive.

"Some of the documents we received were helpful," Shields said of what the FBI gave up in the Seth Jeffs case. "He just had partial stuff. We think that the Warren Jeffs documents will be more complete."