"We understand that others may see the situation differently, and we apologize if any resident deans feel our communication at the conclusion of the investigation was insufficient," they added.

News of the secret search drew immediate criticism from some members of Harvard's faculty.

Harry Lewis, a professor and former dean of Harvard College, said on his blog that he will likely move most of his personal e-mails to another account, keeping his Harvard address just for business. He described the way the school handled the case as dishonorable.

"Why not tell people you are reading their e-mail? Would it not be the honorable thing to do? What is to be gained by not doing that? Other than avoiding, perhaps, the embarrassment of acknowledging that you are doing something to which the targets would reasonably object if they knew it," he wrote.

Attempts to contact Harvard for details on Monday on the search and the handling of it were unsuccessful.

Last month, the school announced that more than half the students implicated in the cheating scandal had been required to withdraw for a time.

More than a hundred students were investigated for plagiarism or for having "inappropriately collaborated" on a course's take-home, open-book spring final exam.

The class was Government 1310: Introduction to Congress, according to The Harvard Crimson, the school's student newspaper.

Many of those who were not forced to withdraw faced disciplinary probation at the Ivy League institution in Cambridge, Massachusetts, and the remaining were cleared.