Associated Press

The Southern Miss basketball program is under investigation by the NCAA for potential rules violations that occurred under former coach Donnie Tyndall, who is now the head coach at Tennessee.

A source close to the program told Bleacher Report that the NCAA's investigation centers on how tuition, living expenses and other fees were paid for "Prop 48" recruits who signed with the Golden Eagles but were academically ineligible out of high school or junior college.

Even though they weren't on scholarship, the players in question enrolled in classes at Southern Miss, lived in off-campus apartments and spent a year earning enough academic credits to make them eligible the following season, when they were placed on scholarship. This is standard practice under NCAA Proposition 48 rules, but the financial support these players may have received is under investigation.

Most of the recruits in question hail from out of state, which would've made their tuition fees even higher. Along with investigating how those fees were paid—and by whom—the NCAA is also looking into the academic records of some of the players, the source said.

Members of the NCAA enforcement staff were in Hattiesburg, Mississippi, last week and this week to interview players and administrators about the potential violations.

Danny Johnston/Associated Press

"The s--t is about to hit the fan," the source said.

Tyndall didn't return a phone call seeking comment Thursday. His replacement, Doc Sadler, has not been interviewed by the NCAA and is not believed to be under investigation.

Three players on Southern Miss' 2014-15 roster—Shadell Millinghaus, Matt Bingaya and Davon Hayes—were Tyndall signees who entered Southern Miss as Prop 48 recruits and are now academically eligible. It is not clear if those players are among those being investigated, as Tyndall signed other players who enrolled at Southern Miss under similar circumstances but are no longer with the program.

Tyndall went 56-17 in two seasons at Southern Miss but failed to lead the Golden Eagles to the NCAA tournament. He left last spring to replace Cuonzo Martin as the head coach at Tennessee. In 2011, Tennessee fired coach Bruce Pearl for violating NCAA rules while at Tennessee and then lying about it to the NCAA.

Jason King covers college basketball for Bleacher Report. You can follow him on Twitter @JasonKingBR.