The U.S. Air Force Academy is investigating whether 40 freshman cadets cheated in their Chemistry 101 lab report assignment, violating the academy's honor code, officials said Monday.

The academy, which initially began investigating 11 of the 500 enrolled cadets, is now probing 40 cadets. According to reports, this is the fourth investigation of cheating involving a group of cadets at the school since 2004, including a 2012 incident that left 78 cadets under suspicion.

“We are sorely disappointed in this extremely small segment of our 4,000-plus cadet population,” Lt. Gen. Michelle D. Johnson, academy superintendent, said in a press release.

“While we believe that the young men and women here will be forged — and forge themselves — into leaders of character for our Air Force and the nation, we also realize that not every one of our 4,000-plus cadets will meet the high standards we expect of them, and we will hold them accountable when they fail to live up to those high standards in accordance with the academy honor code.”

Violations of the honor code, which states that cadets “will not lie, steal or cheat nor tolerate among us anyone who does,” are investigated by the cadet-run honor board, which determines whether the code has been broken.

According to the Academy’s press release: “If found in violation of the Honor Code by representatives of the Cadet Wing, a group made up of upper-class cadets, consequences can range from Honor Remediation, a three to six-month rehabilitation or six-month probation, up to disenrollment.”

David Cannon, a spokesman from the academy, reportedly said that freshmen no longer face mandatory expulsion and, instead, they could be placed on honor probation.