Antioch University says one of its computer systems that contained personal information on about 70,000 people was breached by an unauthorized intruder three times last year.
The university says there is no conclusive evidence any personal information has been stolen but law enforcement officials are investigating.
The breached system contains names, Social Security numbers, academic records and payroll documents for current and former students, applicants and employees going back to 1996.
Antioch University has campuses in Yellow Springs, Ohio; Seattle; Los Angeles and Santa Barbara, California; and Keene, New Hampshire.