Professor Ward Churchill

Adding to a growing list of allegations, controversial University of Colorado professor Ward Churchill appears to have violated copyright law by claiming a reknowned artist's work as his own.

Churchill, whose integrity has been challenged since news broke earlier last month of his paper blaming victims of 9-11 for the attacks, made an Indian-theme serigraph in 1981 called "Winter Attack" and printed 150 copies.

But one of the buyers, Duke Prentup, told Denver's CBS affiliate KCNC-TV of a stunning discovery he made last month while flipping through a book of illustrations by the late artist Thomas E. Mails.

The work signed by Churchill virtually is a mirror image of Mails' 1972 pen and ink sketch, "The Mystic Warriors of the Plains."

KCNC reporter Raj Chohan took a cameraman to Churchill's office Thursday to confront him with the revelation and received an angry response.

Artwork signed by Ward Churchill (KCNC-TV, Denver)

"Get that camera out of my face," Churchill said.

Chohan followed the professor down the hallway to his office, trying to show him Mails' piece and asking to explain why it "looks like you ripped it off."

Original artwork by Thomas Mails(KCNC-TV, Denver)

That prompted Churchill to take a swing at Chohan.

The reporter said: "Sir, that's assault, you can't do that. Can I ask you about this? It looks like you copied it."

Churchill: "I was just grabbed by the arm. And that [camera] gets out of my face."

Chohan: "Sir, we're allowed to take these pictures, this is a public space."

Churchill: "You're not allowed to grab me by the arm."

Chohan: "He didn't touch you sir, we've got it all on tape. Sir, this is called Winter Attack. It's a serigraph by you. It looks like it was copied from Thomas Mails artwork. Can we talk to you about that please?"

Churchill came out of his office several minutes later and agreed to talk, acknowledging his artwork is based on the Mails piece.

He insisted, however, he disclosed that during its initial release.

"It is an original art work by me, after Thomas Mails," Churchill said. "The fact that the purchaser was ignorant of the reality of what was perfectly publicly stated at the time the edition was printed is not my responsibility."

However, no credit was given to Mails on the artwork, and Churchill refused to provide documentation to back his claims.

Intellectual property attorney Jim Hubbell told the Denver station such documentation, if it exists, still would not protect Churchill from copyright infringement unless he had consent from Mails.

The son of the late Thomas Mails told KCNC the family retains the copyright.

"My father invested a great deal of himself in his work, and from that he developed a great fierceness in defending his work," Ryan Mails said. "I cannot imagine he would ever grant permission to anyone to copy one of his pieces."

Controversy erupted around Churchill last month, when one of his essays made it into the national spotlight.

Written shortly after the Sept. 11 attacks, it describes the thousands of American victims who died in the World Trade Center inferno as "little Eichmanns" – a reference to notorious Nazi war criminal Adolf Eichmann – who were perpetuating America's "mighty engine of profit." They were destroyed, he added, thanks to the "gallant sacrifices" of "combat teams" that successfully targeted the World Trade Center towers and the Pentagon.

Churchill resigned his position as head of the Colorado University ethnic studies program but kept his $96,000 per year teaching post. He steadfastly has refused to apologize for his comments.

He's also come under fire for claiming an American Indian heritage, training terrorists, and meeting with Libya's Moammar Gadhafi in the 1980s when the U.S. had banned travel there.

In addition, he's accused of writing essays with passages "almost identical" to those of other authors.

The University of Colorado Regents is probing whether Churchill has violated tenure and expects to announce a decision in March.

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