The heirs of famed Kansas City artist Thomas Hart Benton are suing UMB Bank, claiming it mismanaged his estate, failed to track and maximize the value of his artwork, lost track of more than 100 irreplaceable pieces of art and impermissibly used his art to promote the bank.

The lawsuit, filed in Jackson County Circuit Court, seeks the removal of UMB as trustee of the Benton Trusts, unspecified damages for breach of trust and the cancelation of sales that UMB allegedly entered into without prior authorization or consent.

The 47-page lawsuit, which was first reported by the Wall Street Journal on Wednesday, accuses UMB of failing to “create or follow a plan to promote the legacy of Benton and increase the value of Benton art.”

Benton’s paintings and murals hang in major museums across the United States, including the Nelson-Atkins Museum of Art and the Kemper Museum of Contemporary Art in Kansas City, the Harry S. Truman Presidential Library and Museum in Independence and the Missouri Capitol in Jefferson City. Benton’s art has sold for millions of dollars.

A painter of Midwestern people and landscapes whose work is marked by undulating forms, Benton was a leader, along with Grant Wood and John Steuart Curry, of the American Regionalist art movement that flourished during the 1920s and 1930s. In 1934, he was the first visual artist to appear on the cover of Time magazine.

Credit Julie Denesha Benton's home at 36th and Belleview in Kansas City, now a historic site.

Benton, who was born in Neosho, Missouri, died in his Kansas City studio and home in January 1975 at age 85. His wife, Rita P. Benton, died 11 weeks later at age 79. The couple had two children, Jessie Benton and Thomas Piacenza, known as “T.P.,” who died in 2010 and left no children.

The lawsuit was filed by Jessie Benton of Chilmark, Massachusetts, and her three children: Anthony Gude of Frankfort, Kansas; Daria Lyman of Cambridge, Massachusetts; and Cybele Benton McCormick of Vineyard Haven, Massachusetts.

UMB has served as a trustee of the two Benton trusts since 1979.

In a statement, UMB President and CEO Jim Rine said the bank won’t comment on the allegations in the lawsuit.

But he said the bank “values the relationships with individuals and families for whom it has the privilege of providing trust management services.”

“Despite our extensive efforts to address issues presented, the Benton family and its representatives have chosen to resolve alleged issues through litigation,” Rine said. “We take our role as a trustee for art and other assets seriously and will directly address and defend the misguided allegations made in the lawsuit. We look forward to this matter being resolved as quickly and fairly as possible.”

When they were established, the Benton trusts’ property included cash, stock, real estate and hundreds of paintings, drawings and lithographs by Benton and other artists, according to the lawsuit. They also included correspondence between Benton and President Truman, original manuscripts of articles and books written by Benton and other assets.

The suit alleges that UMB violated the trusts’ requirement that UMB maintain the market value and demand for Benton’s art by selling his work prematurely, failing to obtain valid appraisals, failing to complete an inventory of all of Benton’s artwork and failing to track it properly.

“Likely over one hundred irreplaceable pieces of art are unaccounted for and lost from the Benton Trusts because of UMB’s actions and inactions,” the lawsuit states.

The suit also accuses UMB of using the artwork of the Benton Trusts “as if it were its own.” It says the Kemper Museum, which was co-founded by the late R. Crosby Kemper Jr., the longtime chairman and CEO of UMB Bank, has several Benton works, including one shown as being gifted by Kemper to the museum. In fact, the suit says, an addendum to Benton’s will bequeathed it to the Nelson Gallery Foundation.

Breeze Richardson, a spokeswoman for the Kemper Museum, said the museum's records show the work in question was gifted to the museum by Kemper and his wife in 2000. She said they purchased it from a commercial gallery.

The suit notes that UMB hung Benton works at various UMB locations, used them in the bank’s advertising and charitable events and used them to promote the bank’s expertise in “Fine Art Management Services.”

“UMB’s use of artwork and property from the Benton Trusts has been without notification to the beneficiaries and without compensation to the Benton Trusts,” the suit alleges.

The suit also alleges that UMB moved Benton artwork to a vault that was not climate-controlled after spending hundreds of thousands of dollars to construct a vault that was climate-controlled.

Andre Boyda, one of the lawyers representing Benton’s heirs, said the family was “devastated by what we alleged in the petition.”

“They felt like their trust was violated,” he said. “They felt a commercial bank like that would abide by what it promised to (Jessie’s) father and track and trace the estate and care for his legacy.”

The Nelson-Atkins Museum staged a retrospective of Benton’s work four years ago that looked at Benton’s connection to the film industry. The museum claims to hold the largest public collection of art by Benton, including a bequest of 45 paintings and drawings.

Boyda said it was during that retrospective that Jessie Benton discovered that Benton’s art had been moved from a climate-controlled vault to one that wasn’t climate-controlled.

“She had not been in the vault for a very, very long time, and she went down there and they had moved the collection from the vault she last saw, which was climate-controlled, to a converted safety deposit box vault,” Boyda said. “And she thought, ‘Oh, my God, where have all the pieces gone?’ And that is when she reached out to me and asked me to start looking into stuff.”

Benton taught at the Art Students League in New York City where one of his pupils was Jackson Pollock. He later taught at the Kansas City Art Institute and School of Design.

His Kansas City home and carriage house studio, at 3616 Belleview Ave., are state historic sites that have been preserved nearly unchanged since his death. The house contains 13 of his works.

Read the lawsuit here

Editor's note: This story was updated on Dec. 24 to include the comments of a spokeswoman for the Kemper Museum of Contemporary Art.

Dan Margolies is a senior reporter and editor at KCUR. You can reach him on Twitter @DanMargolies.