The day almost two years ago when Harvard Business School informed Francesca Gino, a prominent professor, that she was being investigated for data fraud also happened to be her husband’s 50th birthday. An administrator instructed her to turn in any Harvard-issued computer equipment that she had by 5 p.m. She canceled the birthday celebration she had planned and walked the machines to campus, where a University Police officer oversaw the transfer.

“We ended up both going,” Dr. Gino recalled. “I couldn’t go on my own because I felt like, I don’t know, the earth was opening up under my feet for reasons that I couldn’t understand.”

The school told Dr. Gino it had received allegations that she manipulated data in four papers on topics in behavioral science, which straddles fields like psychology, marketing and economics.

Dr. Gino published the four papers under scrutiny from 2012 to 2020, and fellow academics had cited one of them more than 500 times. The paper found that asking people to attest to their truthfulness at the top of a tax or insurance form, rather than at the bottom, made their responses more accurate because it supposedly activated their ethical instincts before they provided information.

Though she did not know it at the time, Harvard had been alerted to the evidence of fraud a few months earlier by three other behavioral scientists who publish a blog called Data Colada, which focuses on the validity of social science research. The bloggers said it appeared that Dr. Gino had tampered with data to make her studies appear more impressive than they were. In some cases, they said, someone had moved numbers around in a spreadsheet so that they better aligned with her hypothesis. In another paper, data points appeared to have been altered to exaggerate the finding.

Their tip set in motion an investigation that, roughly two years later, would lead Harvard to place Dr. Gino on unpaid leave and seek to revoke her tenure — a rare step akin to career death for an academic. It has prompted her to file a defamation lawsuit against the school and the bloggers, in which she is seeking at least $25 million, and has stirred up a debate among her Harvard colleagues over whether she has received due process.