Mississippi State says it is working with the NCAA because of a 'potential recruiting irregularity' in the football program.
The school says the examination has lasted several months and that it is close to being finished.
NCAA spokesperson Stacey Osburn confirmed the NCAA and Mississippi State were "working cooperatively", but did not have any further comment.
Mississippi State receivers coach Angelo Mirando resigned his position Sunday, citing "unforeseen personal issues". It is unclear if Mirando's departure had anything to do with the current investigation.
Head football coach Dan Mullen has not elaborated on the reason for Mirando's resignation.
Mississippi State opens its season with a home game against Jackson State Sept. 1 at Davis Wade Stadium.