BOULDER - In a relentlessly critical report, University of Colorado investigators said Tuesday that the professor who likened some of the World Trade Center victims to a Nazi repeatedly fabricated his research, plagiarized others' work and strayed from the "bedrock principles of scholarship."

Four of the five members of the investigative panel said ethnic studies professor Ward Churchill should be suspended without pay, though one said he should be fired. University officials said they expect to decide his fate by June 8 and refused to speculate about what might happen.

Churchill called the report "a travesty."

"Some of this I see as being transparently ridiculous, laughable," he told The Associated Press. "I feel, in a weird way, actually sort of validated they would put themselves through such contortions" to condemn his work.

The report has been eagerly awaited by critics of Churchill, a defiant and polarizing figure who became a poster child in a national debate over academic freedom. His essay, written in the hours after the 2001 terrorist attacks on the United States, came to light last year and brought immediate denunciations from the governor, state lawmakers and relatives of Sept. 11 victims in New York.

Gov. Bill Owens said again Tuesday that Churchill has tarnished the university's reputation and should resign.

"Unfortunately, as the lengthy process continues, the prolonged presence of Ward Churchill at CU besmirches the reputation of a fine university and its many outstanding teachers," Owens said.