An outside investigator has completed his review of the academic scandal at the University of North Carolina (UNC) - Chapel Hill

According to the Associated Press, Kenneth Wainstein, a former high-ranking official at the U.S. Justice Department, found that more than 3,100 students took "paper classes." At least half those were student-athletes and the classes rarely met, if at all, serving as  "GPA boosters."

The classes were offered in UNC's African and Afro-American Studies department, the former chairman of which was indicted on fraud charges relating to the classes. Wainstein said this "shadow curriculum" lasted some 20 years and were around before Julius Nyang'oro became chairman.

Students in these classes needed only write one paper to earn a final grade - A's and B's - in the class and department officials signed off.

"Mr. Wainstein has found that the wrongdoing at Carolina lasted much longer and affected more students than previously known. The bad actions of a few and the inaction of others failed the University's students, faculty and alumni, and undermined the institution as a whole," UNC - Chapel Hill Chancellor Carol L. Folt said in a press release. "This conduct could and should have been stopped much earlier by individuals in positions of influence and oversight, and others could have sounded the alarm more forcefully."

According to the release, Wainstein discovered that academic advisers steered the majority of the "paper class" attendees toward the courses. According to ESPN, the investigator also found that coaches knew their players were taking easy classes, but were not aware of what was actually going on.

The NCAA first investigated UNC - Chapel Hill in 2010 for some of its student-athletes allegedly receiving improper benefits. The school could face further sanctions for the findings in Wainstein's report. UNC - Chapel Hill could dismiss staff members and the NCAA could levy sanctions for the athletic department.