The court filing claims the FLDS members contributed labor, built houses and improved the farm believing they would live and work there forever.
If Bruce R. Wisan, who has overseen the UEP Trust since 2005, proceeds with a plan to sell the farm, they want proceeds turned over to them as compensation for those contributions. They also claim Wisan improperly evicted them from their homes at the farm after they refused to work for him.
Wisan said Wednesday he does not believe the plaintiffs have much of a case.
"They are claiming some kind of right that someone said they could work there," Wisan said. "I don't think they have a very good case legally, but we will have to look at it."
Wisan said he believes the lawsuit is "probably part of Willie Jessop wanting to go full force against the trust." Jessop is a member of the Fundamentalist Church of Jesus Christ of Latter Day Saints and has emerged in recent months as a spokesman for the sect and its members.
Wisan forced a sheriff's sale of the 600-acre farm, then operated by the FLDS members, last year to satisfy a $8.8 million default judgment against former UEP trustees.
On behalf of the trust, Wisan then bought the farm and its operating stock for $4.3 million and arranged to sell it for $5.5 million to Jonathan and Hyrum Harker, who were never FLDS members and whose grandfather, Parley J. Harker, an FLDS member, started the farm.
But the sale was stopped after Sterling and William Harker, two of Parley J. Harker's sons and also former FLDS members, objected to not being compensated. That lawsuit, which seeks $10 million in damages, is still pending against the trust and its current and former trustees.