CHAPEL HILL, N.C. — The probe into North Carolina's football program added another prong. Along with it came another batch of question marks to cloud a promising season.

The school's announcement that the investigation of the Tar Heels' program has expanded into possible academic misconduct — one involving players and a woman who coach Butch Davis previously hired to tutor his son — seemed to raise as many questions as it attempted to answer.

How many players may have been involved? Which ones? What were the possible acts of misconduct? And what effect will this uncertainty have on a team expected to challenge for ACC supremacy?

"We are looking into improprieties that existed outside the classroom," athletic director Dick Baddour said Thursday night when asked about the specific actions that led to the probe.

Baddour would not identify the players or even estimate any numbers, saying "to put a bracket around it could be misleading." He declined to get into many specifics.

The announcement came nine days before the 18th-ranked Tar Heels' opener against No. 21 LSU in Atlanta, and roughly two months after the NCAA began an investigation into whether two key players — defensive tackle Marvin Austin and receiver Greg Little — received improper benefits from agents.