Harvard University has admitted to secretly photographing students in classes in 10 lecture halls, in which more than 2,000 students were enrolled, as part of a study of classroom attendance.
Harvard President Drew Faust says that she takes this matter "very seriously" and will have the case reviewed.
The findings of the study were apparently released at a conference this fall, but the researchers never revealed how the data was collected.
The study was done by Harvard's Initiative for Learning and Teaching, which is overseen by Vice Provost Peter Bol, and was authorized by the school's Institutional Review Board.
"Professor Bol has reached out to every faculty member involved and has already spoken in person to all but two. He will continue that effort to ensure that the faculty have full details," the school said in a statement.
"In addition, he has committed to informing every student – using enrollment data – whose image may have been captured anonymously and subsequently destroyed as part of the research," it added.
The researchers say the study was not designed to trick or identify individual students. The images have all been destroyed, and only the data was kept for research use, Bol said.
The latest revelations come a year and a half after the university apparently searched thousands of Harvard email accounts secretly. That prompted the Ivy League school to implement new privacy policies on electronic communications.