The University of Michigan has received a notice of allegations from the NCAA related to the sign-stealing investigation, the school confirmed to CNN on Sunday.

An NCAA spokesperson also confirmed to CNN it has sent Michigan the notice of allegations to “the school and involved parties in the Michigan investigation.”

“To protect the integrity of the infractions process as the case progresses forward, the NCAA will not provide any further comment on the specifics included,” the spokesperson continued.

Michigan, who come into this college football season as reigning national champions and now without former head coach Jim Harbaugh, faced a season filled with plenty of questions surrounding the team – and potential NCAA punishment.

Last year, Harbaugh was suspended for the team’s first three games, a self-imposed sanction by Michigan’s athletics department, amid allegations of recruiting violations.

The NCAA opened a second investigation into the Wolverines in October for alleged sign-stealing, leading to the suspension and subsequent resignation of Michigan football analyst Connor Stalions. Linebackers coach Chris Partridge was later fired, but Michigan didn’t elaborate on why he was let go.

Harbaugh has denied knowledge of any scheme to steal other teams’ signs, and – after initial protest – accepted a three-game suspension, upping his total games away from the Michigan sideline to six.

After winning the Wolverines’ first national championship since 1997, Harbaugh left Michigan in January to become the head coach of the NFL’s Los Angeles Chargers.

Earlier this month, the NCAA released its findings of the recruiting violations investigation and handed Harbaugh a four-year show cause order.

Michigan now has 90 days to respond, according to the NCAA.