NEW YORK

A Columbia University Teachers College professor whose colleagues found a noose hanging from her office door is now being accused of plagiarism, a charge she said is part of efforts to intimidate her because she is Black.

The school said Wednesday it imposed sanctions against Dr. Madonna G. Constantine following an investigation that uncovered “numerous instances in which she used others’ work without attribution in papers she published over the past five years.”

Her lawyer, Paul J. Giacomo Jr., said his client could prove her innocence and called the school’s investigation “extremely underhanded from the beginning.” He said he would appeal the sanctions, which neither side would disclose.

The inquiry into Constantine, an education and psychology professor who has written extensively about race, was launched in 2006, long before the noose was discovered in October, the school stated.

“The investigators found a real pattern, two dozen instances of similar language from three people who came forward separately,” Teachers College spokeswoman Marcia Horowitz said. “Dr. Constantine’s explanation was not credible.”

In a written statement, Constantine said she had been subjected to “a conspiracy and witch-hunt by certain current and former members of the Teachers College community.”

Giacomo said Constantine had “clearly” been targeted because of her race, and he said he believed the noose incident and the plagiarism investigation might be linked.

“There’s been an effort to intimidate my client, that’s clear,” Giacomo said.

Horowitz dismissed his claims, saying “it is both absurd and untrue that racism had anything to do with this report.”

“Teachers College has zero tolerance for racism, discrimination or prejudice of any kind,” she said.

The discovery of the noose, a symbol of lynchings in the South, on Constantine’s door roiled the elite university’s campus and gained national attention.