A one-minute call made from the University-issued phone of Ole Miss football coach Hugh Freeze to a number associated with a female escort service was raised as a potential issue in the back-and-forth between the university’s legal counsel and the attorney for former Rebels football coach Houston Nutt, according to records and correspondence obtained by USA TODAY Sports.

Ole Miss announced Thursday evening that Freeze had resigned, hours after the school said it would provide a written statement to USA TODAY Sports regarding the phone call.

Athletics director Ross Bjork said in a news conference following the announcement that the resignation did not involve NCAA allegations but was based on a pattern of inappropriate conduct.

Bjork said if that the information they had uncovered had been public, the reason for the decision would be clear, acknowledging that if Freeze had not resigned the school would have "exercised the termination clause in the contract for moral turpitude."

On July 13 — one day after Nutt filed a federal lawsuit against Ole Miss alleging that the school violated the terms of its severance agreement — Nutt’s attorney, Thomas Mars, sent an e-mail to Lee Tyner, the school’s general counsel, referencing a “phone call Coach Freeze made that would be highly embarrassing for all of you and extremely difficult to explain.”

The call, which was made on the evening of Jan. 19, 2016, to a Detroit (313) area code, lasts just one minute, according to e-mails exchanged between the two parties. But the phone number is associated with several Web sites advertising a female escort based in Tampa, Fla., USA TODAY Sports has independently confirmed. The phone number has been disconnected.

According to Mars, the records do not show Freeze immediately redialing a different or similar number, nor do other calls to a 313 number appear in the phone records covering the days Mars requested.

Responding on July 14, Tyner rebuffed a suggestion from Mars that the phone call might be connected to Ole Miss' ongoing NCAA infractions case, saying the school had inquired into the matter and that “the call to the Detroit number that lasted one minute (or less) appears to be a misdial.”

Mars shared the correspondence with USA TODAY Sports.

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Bjork said when the number — which was not redacted among other calls deemed personal — was brought to his attention, school officials looked closer.

“We proactively looked into the rest of his phone records and found a concerning pattern,” Bjork said.

The exchange over the phone call highlights the ugliness between Ole Miss and Nutt as the school attempts to fight one of the most expansive NCAA infractions cases in recent memory.

Nutt alleges in his lawsuit that Ole Miss officials, including Freeze and athletics director Ross Bjork, conspired to smear him in late January 2016 by telling several local and national reporters in “off the record” conversations that most of the violations the NCAA had accused the school of occurred during the Nutt era.

That false narrative taking hold in some media accounts — in reality, 9 of the 13 alleged violations in the first Notice of Allegations took place under the Freeze regime — was an intentional strategy promoted by Ole Miss, Nutt’s lawsuit contends, to help save the school’s highly-ranked recruiting class right before National Signing Day.

The case against Ole Miss brought by the NCAA has since expanded to include 21 allegations against the football program, including lack of institutional control and failure to monitor, which could lead to significant penalties targeted at Freeze.

Nutt contends the false narrative has hurt his prospects of landing another Football Bowl Subdivision head coaching job and that it violated a non-disparagement clause in his termination agreement. Ole Miss officials have not commented on the lawsuit.

In putting together the lawsuit, Mars paired phone calls made from Freeze, Bjork and head of communications Kyle Campbell to reporters around the time Yahoo! Sports reported that Ole Miss had received its Notice of Allegations from the NCAA.

Mars has now expanded his search, this week requesting all of Freeze’s phone records beginning in June 2012, he told USA TODAY Sports.