Defenders of a Teachers College professor accused of plagiarism came forward yesterday to accuse the school of racial bias, even as the professor said her accusers had plagiarized her work first.

Madonna Constantine, a psychology professor who studies race, came into the spotlight last fall when a hangman’s noose was found on the doorknob of her office at Teachers College, which is affiliated with Columbia University.

Ms. Constantine’s lawyer, Paul Giacomo, publicized scathing letters yesterday, attributed to one of her colleagues, Barbara Wallace, and one of her former students, defending Ms. Constantine after Teachers College published the findings this week of a two-year investigation into the allegations of plagiarism.

“These accusations are not believable,” Ms. Wallace wrote. “I absolutely believe this is just an attempt to besmear her name and reputation.”

Ms. Wallace noted in her letter that she is the only other black female professor with tenure at the school.

Ms. Constantine has been accused of using the work of two students and a colleague, Christine Yeh, without attributing it, in papers published over five years.

“The truth is that I am not a liar, nor am I a cheater,” Ms. Constantine wrote in a two-page statement released yesterday that accused the president of Teachers College, Susan Fuhrman, of “blackmail and intimidation.”

A spokeswoman for the school, Marsha Horowitz, said Teachers College would not discuss the contents of the report.

“Both Teachers College and investigators stand by the completeness and integrity of the report,” Ms. Horowitz, who is also a publicist at Rubenstein Associates, said.