The head of NCAA enforcement says academic misconduct has been on the rise in college athletics and his department is handling 20 open investigations.

Vice president of enforcement Jon Duncan said Wednesday in an interview with The Associated Press the cases involve both prospective and incoming athletes trying to become eligible for college competition, and enrolled athletes receiving impermissible assistance from university and athletic department personnel.

Eighteen of the cases involve Division I schools, though NCAA policies preclude Duncan from revealing which programs are under investigation.

North Carolina has been the focus of the NCAA’s most high-profile infractions case involving academics. Last year an independent investigator found that hundreds of Tar Heels athletes over nearly two decades were steered toward sham classes that gave out high grades for little work.