Updated

Ohio State football coach Urban Meyer was placed on paid administrative leave Wednesday as the university investigates what he knew about domestic abuse claims against an assistant coach who was fired last week.

Offensive coordinator Ryan Day will serve as acting head coach for the Buckeyes, expected to be one of the top teams in the nation again this season.

The announcement was made hours after the ex-wife of former wide receivers coach Zach Smith alleged publicly that she told Meyer's wife in 2015 that Smith had assaulted her.

Courtney Smith made the allegations in an interview with the digital sports network Stadium and provided text messages to reporter Brett McMurphy.

"Shelley said she was going to have to tell Urban," Courtney Smith told Stadium. "I said: 'That's fine, you should tell Urban.'"

If Courtney Smith's allegations are confirmed, the Meyers could be in violation of Title IX policy on reporting allegations of domestic violence against university employees. Shelley Meyer is a registered nurse and an instructor at the university.

Smith was fired July 23 after an Ohio court granted Courtney Smith a domestic violence protective order. The couple divorced in 2016.

Zach Smith was charged in May with misdemeanor criminal trespass. At the time of the charge, Zach Smith's attorney said Courtney Smith had accused him of driving to her apartment after she told him they would meet elsewhere so he could drop off their son. Zach Smith pleaded not guilty last month. A hearing has been scheduled for Friday.

Zach Smith was accused of aggravated battery on his then-pregnant wife in 2009 while he was a graduate assistant on Meyer's staff at Florida. The charge was dropped because of insufficient evidence. Urban Meyer brought Smith, the grandson of late Buckeyes coach Earle Bruce, to Ohio State in 2012.

Two police reports filed in 2015 in Ohio's Powell County, after the Smiths separated in June of that year, accused Zach Smith of abuse. Charges were never filed.

At Big Ten media days, Meyer said he knew of the incident in 2009 and he and Shelley Meyer addressed it with the Smiths. Asked about the 2015 incident alleged by Courtney Smith, Meyer said: "I can't say it didn't happen because I wasn't there. I was never told about anything and nothing ever came to light. I've never had a conversation about it. I know nothing about it. First I heard about that was last night. No, and I asked some people back at the office to call and say what happened and they came back and said they know nothing about it."

Meyer is one of the most successful coaches in college football history, with three national championships and an .851 winning percentage in 16 seasons at Bowling Green, Utah, Florida and now Ohio State, the team he grew up rooting for in Northeast Ohio.

Meyer won national championships with Florida in 2006 and '08, but his teams also had more than two dozen players get into trouble with the law. He resigned twice at Florida, citing health reasons. First in 2009 season after the Gators lost the Southeastern Conference championship game while trying to repeat as national champs. He changed his mind soon after and coached another season. The Gators went 8-5 and this time he stepped down for good.

Meyer was out of coaching for a season, but was hired by Ohio State in November 2011 to replace coach Jim Tressel, who was fired before that season for lying to the NCAA and university of about rules violation committed by some of his players.

Since returning to coaching, Meyer's program has been one of the most dominant in college football and his players and coaches have mostly stayed out of major trouble.

Meyer did face some criticism in 2013 for allowing running back Carlos Hyde to return to the team after he was charged with striking a woman in a bar. The case was dropped by police when the woman chose not to pursue charges, but Hyde was suspended three games by Ohio State.

The Associated Press contributed to this report.