The NCAA has formally charged the University of Mississippi with dozens of rules violations in three sports, multiple sources told Yahoo Sports.

The school has received a Notice of Allegations from the NCAA enforcement staff alleging roughly 30 violations in football, women’s basketball and track and field, sources told Yahoo. It is unclear at present what the breakdown is in terms of violations by sport. The NCAA does not comment on current, pending or potential investigations.

Calls to officials at Mississippi were not immediately returned Friday. Southeastern Conference spokesman Herb Vincent declined comment to Yahoo Sports.

This is the latest step in a long, laborious NCAA investigation, part of which predates football coach Hugh Freeze’s arrival at Ole Miss in 2012. Yahoo Sports first reported about the investigation in October 2014.

According to standard NCAA protocol, Ole Miss and/or other parties charged with violations have 90 days to respond to the allegations. Unless there is agreement on the facts and the case can be resolved by summary disposition, a Committee on Infractions hearing date will be established. The COI generally meets six times a year; it most recently met last week.

If there is a hearing, NCAA enforcement will present its case and the school can present its side. A Committee On Infractions report, detailing any penalties that are to be assessed, generally is issued six to eight weeks after the hearing.

Mississippi’s football recruiting successes in recent years under Freeze have taken the Southeastern Conference by storm – and rankled some rivals. Multiple SEC coaches and administrators have voiced concerns about Ole Miss to the conference office, sources said. Shortly before National Signing Day in 2013, Freeze took to Twitter and challenged anyone who had facts showing the Rebels were breaking rules to email the school’s compliance office.

Ole Miss’ current recruiting class is ranked No. 4 nationally by Rivals.com. National Signing Day is Wednesday.

This past football season, Mississippi offensive tackle Laremy Tunsil – one of the highest-rated recruits in program history – sat out seven games for accepting impermissible benefits. Tunsil, according to an Ole Miss release, was found to have accepted “use of three separate loaner vehicles over a sixth-month period without payment, a four-month interest-free promissory note on a $3,000 down payment for purchasing a used vehicle, two nights of lodging at a local home, an airline ticket purchased by a friend of a teammate, and one day use of a rental vehicle. In addition, it was determined that Tunsil was not completely forthcoming when initially questioned by NCAA investigators regarding the loaner vehicles.” Tunsil has since declared for the NFL draft and is expected to be a high first-round pick.

It was not the only controversy involving a star Ole Miss player last season. Defensive lineman Robert Nkemdiche, like Tunsil a five-star member of the Rebels’ breakthrough 2013 recruiting class, was suspended from the Sugar Bowl after a bizarre incident at an Atlanta hotel in December. Nkemdiche fell about 15 feet from a room at the Grand Hyatt, sustaining minor injuries after breaking a window. The junior was charged with marijuana possession. He also has declared for the NFL draft.