RALEIGH, N.C. — An alarming lack of institutional oversight at the University of North Carolina allowed an academic fraud scandal to run unchecked for nearly two decades and has the school reeling from the scandal’s fallout.

The latest investigation found that university leaders, faculty members and staff missed or just ignored flags that could’ve stopped the problem years earlier. More than 3,100 students — about half of them athletes — benefited from sham classes and artificially high grades in the formerly named African and Afro-American Studies department (AFAM) in Chapel Hill.

A report by former U.S. Justice Department official Kenneth Wainstein indicates that the bogus classes ended in 2011. The university has since overhauled the department and implemented new policies, but it must wait to find out whether the damaging new details lead to more problems with the agency that accredits the school. The NCAA, which has reopened its investigation into academic misconduct, could also have concerns of lack of institutional control.

“Bad actions of a relatively few number of people were definitely compounded by inaction and the lack of really appropriate checks and balances,” Chancellor Carol Folt said Thursday. “And it was together that really allowed this to persist for such a length of time.”

The issues outlined in the report were jarring, including the clear involvement of athletic counselors who steered athletes into those bogus classes. From 1993 to 2011, those classes required no attendance and required only a research paper that received A’s and B’s without regard for quality, a cursory review often performed by an office secretary who also signed the chairman’s name to grade rolls.

Those two people — retired administrator Deborah Crowder and former chairman Julius Nyang’oro — were at the center of the scheme. But Wainstein’s report also notes school officials failed to act on their suspicions or specific concerns that came to their attention. It all added up to a series of missed chances to stop the fraud and instead allowed it to escalate.

Accreditation questions are now facing the university.

The Southern Association of Colleges and Schools’ Commission on Colleges had placed the campus on its watch list until this summer and required the school to allow students who took a bogus course to take another for free. The commission will send the school a letter in the next few days asking administrators to demonstrate they are still in compliance with standards required for the seal of approval, SACS President Belle Wheelan said.

“What we would do is ask them is, this is bigger than you thought it was, what are you going to do now? It’s a mess,” Wheelan said.

The school’s response will be addressed by the 77-member board at its meeting in December, she said.