KNOXVILLE, Tenn. (AP) — The NCAA investigation at his former school lingered over Donnie Tyndall before he ever coached a game for Tennessee, and now his unethical actions at Southern Mississippi have led to his firing after only one season.

The decision to part ways with Tyndall on Friday leaves the Volunteers once again searching for someone to stabilize a men's basketball program that has recently been in constant upheaval.

Tennessee athletic director Dave Hart said it would be fair to say it was a mistake to hire Tyndall, who Hart said acknowledged deleting emails that could have been relevant to the Southern Mississippi investigation. In his termination letter, Hart states the emails were deleted by Tyndall on or around Nov. 18, less than two weeks after Southern Mississippi announced it was under investigation.

"Knowing what I know now, is that a mistake?" Hart asked. "Probably. ... But, you know, there are a lot of coaches out there that have a transgression in their history somewhere that had an opportunity to do better. I was convinced at the time of the hire that Donnie had learned his lesson from Morehead State. ... Obviously if we'd known (then) what we know now, we would have moved in another direction."

Morehead State went on probation for two years in August 2010 because of violations related to booster activity under Tyndall's watch.

When details surfaced about Tyndall's conduct at Southern Miss, Hart took action, firing Tyndall on Friday at a 7 a.m. meeting. The university is apparently looking to quickly sever all ties with Tyndall: Hart spoke at a press conference in the Ray Mears Room of Thompson-Boling Arena with a black curtain hung over a wall to cover a mural of Tyndall.

Tyndall's contract was set to run through March 2020 and pay him $1.6 million annually, but Hart said Friday that the terms should prevent the school from owing him any more money.

The coach went 16-16 in his lone season at Tennessee. Hart said the university did its due diligence before hiring Tyndall and that he was "very comfortable" with his vetting of Tyndall.

But Hart said he would take a different approach in finding a successor. He will use a search firm for this upcoming hire, something he didn't do when selecting Tyndall or deciding on Butch Jones as Tennessee's football coach in December 2012. Hart said he wouldn't consider anyone with a history of NCAA violations.

Tyndall's successor will become Tennessee's third coach in as many years — and fourth in six years. Bruce Pearl was fired amid an NCAA investigation in 2011. Cuonzo Martin left for California last year after three seasons.

"One of the things we've strived for is to get stability," Hart said. "We had hoped when we hired Donnie that we'd have that element in our men's basketball program. That is not how it's panned out as we stand here today."

Al Pinkins, an assistant on Tyndall's staff who didn't work with him at Southern Mississippi, will serve as interim coach while Tennessee conducts its search.

Southern Miss revealed it was under investigation in November, about a week before Tennessee's season opener. Southern Mississippi announced in January it had self-imposed a postseason ban for the 2014-15 season.

In his termination letter, Hart said Tyndall acknowledged deleting emails from an "account maintained at a prior institution." Hart said it's highly likely the NCAA will determine Tyndall failed to cooperate and that he failed to disclose "material information concerning violations of NCAA rules" during Tennessee's hiring process.

The AD also said In his termination letter that it's "highly likely" that the NCAA will find "Level I and/or Level II violations relating to academic misconduct and impermissible financial aid" occurred while Tyndall was at Southern Miss.

Tyndall's Tennessee contract allows the school to fire him for cause if he is found to have committed an NCAA Level I or Level II violation "whether the conduct occurred during (Tyndall's) employment with the university or another NCAA-member institution."

Tyndall issued a statement through his lawyer Stuart Brown in which the coach said he was "extremely saddened by my separation from Tennessee" and apologized to his players, coaching staff and Volunteer fans.

"In the past months, I learned that violations of NCAA rules occurred in the Southern Miss men's basketball program when I was that program's head coach. That surprised and disappointed me," Tyndall said. "During my time at Southern Miss, I believed that our program followed NCAA rules and worked well with the university's administration to maintain an atmosphere of rules compliance.

"NCAA rules prevent me from being more specific. However, as the head coach at that time, I accept ultimate responsibility for violations that occurred. While at Tennessee, I cooperated with the NCAA investigation process, and I will continue to do so."

Southern Mississippi athletic director Bill McGillis issued a statement Friday saying that "in order to maintain the integrity of the investigation, and pursuant to NCAA policy, we cannot comment further regarding any details of the case at this time."