It looks like students might not be the only ones cheating at Harvard lately: former Harvard psychology professor Marc Hauser is guilty of six cases of data fabrication or manipulation in work supported by grants from the National Institutes of Health, according to a report by the federal Office of Research Integrity, the Boston Globe reported this week.

The report found skewed data in some of Hauser’s language and cognition studies involving monkeys. One of Hauser’s papers has been retracted and two have been revised, while the rest of the fabrications were found in unpublished writings.

Hauser resigned from Harvard in 2011, after the University closed a three-year investigation into Hauser’s suspected research misconduct. Harvard investigators had found him “solely responsible” for eight cases of research misconduct and sent their findings to the Department of Health and Human Services, which launched a federal investigation.

Hauser “neither admits nor denies committing research misconduct,” according to the report.

“Although I have fundamental differences with some of the findings, I acknowledge that I made mistakes,” Hauser said in a statement. “I let important details get away from my control, and as head of the lab, I take responsibility for all errors made within the lab, whether or not I was directly involved.”