Utah has launched an organized-crime investigation into a polygamist sect and its fugitive leader Warren Jeffs, now on the FBI's 10 Most Wanted list.

Jeffs is already wanted on Utah and Arizona charges alleging he arranged plural marriages of underage girls. Attorney General Mark Shurtleff said Monday that his office is also looking at Jeffs and his church for "double books, cooking books, offshore accounts and fraud."

"I believe Warren Jeffs ran the FLDS church and the UEP as an organized crime-type setup," Shurtleff said. "We just have to get the evidence to prove it."

The UEP is the United Effort Plan trust, the $110 million financial arm of the Fundamentalist Church of Jesus Christ of Latter Day Saints, which owns businesses and property in the Hildale, Utah, and Colorado City, Ariz., where the church is based.

Shurtleff has contended Jeffs used the UEP to reward or punish followers. The attorney general petitioned last year to take control of the trust, and a special fiduciary was appointed to oversee it.

"We've been following closely what the special fiduciary is uncovering from records and so forth," Shurtleff said. "It has been very informative, we'll say."

The FLDS church is one of a number of polygamist sects in and near Utah. Followers believe The Church of Jesus Christ of Latter-day Saints, or Mormon church, went the wrong direction when it abandoned polygamy more than a century ago as Utah was seeking statehood. Estimates of the number of polygamists range from 30,000 to 100,000.

Jeffs has been on the run for years. On Saturday, he was added to the FBI's Ten Most Wanted Fugitives list, and the federal reward for him was boosted to $100,000.