Attorney General Mike Hunter of Oklahoma announced his resignation on Wednesday, a day after a local newspaper said it had questioned him about an extramarital affair.
“Regrettably, certain personal matters that are becoming public will become a distraction for this office,” Mr. Hunter said in a statement on Wednesday. “I cannot allow a personal issue to overshadow the vital work the attorneys, agents and support staff do on behalf of Oklahomans.”
He said he would officially step down on Tuesday.
His abrupt announcement came after The Oklahoman said it had sent him questions on Tuesday night about an extramarital affair that it said it had confirmed through people familiar with the situation.
Mr. Hunter, a Republican, filed for divorce on Friday from Cheryl Hunter, his wife of 39 years, the newspaper reported. The Oklahoman reported that, according to the people it had spoken with, the affair had been with an employee of the state Insurance Department who had filed for divorce in April from her husband of 25 years.
Under the state Constitution, Gov. Kevin Stitt, a fellow Republican, can appoint Mr. Hunter’s replacement to serve until the next election in 2022, Mr. Stitt’s spokeswoman, Carly Atchison, said.
“The Attorney General informed me of his resignation this morning and I respect his decision to do what he thinks is best for his office and the State of Oklahoma,” Mr. Stitt said in a statement on Wednesday. “I know he is going through a difficult time and I wish him, his family, and the employees of his office well.”
Ms. Hunter declined to comment on Wednesday. She told The Oklahoman on Tuesday that “I am heartbroken and my priorities are to take care of my sons, my daughter-in-law, my grandson and my parents.”
Gov. Mary Fallin had appointed Mr. Hunter to serve as attorney general in February 2017 after Scott Pruitt, the previous attorney general, resigned to become administrator of the Environmental Protection Agency under President Donald J. Trump.
Mr. Hunter had previously served as first assistant attorney general under Mr. Pruitt before Ms. Fallin named him secretary of state and special legal counsel.
From 2010 to 2015, Mr. Hunter was the chief operating officer of the American Bankers Association, and from 2002 to 2009, he was executive vice president and chief operating officer of the American Council of Life Insurers, Ms. Fallin’s office said when she announced his appointment as attorney general.
Mr. Hunter also served six years in the Oklahoma House of Representatives, representing District 85 in Oklahoma City, according to his office.
As attorney general, Mr. Hunter was one of a number of Republicans who joined in support of a lawsuit filed by the Texas attorney general that challenged the 2020 election results in Pennsylvania, Georgia, Michigan and Wisconsin, four states that Mr. Trump had lost to President Biden. The Supreme Court rejected the lawsuit in December.
Mr. Hunter had also made fighting the opioid crisis a top priority.
In 2019, he led the state’s case in the first civil trial against an opioid manufacturer, Johnson & Johnson, the New Jersey-based medical giant, which produced a fentanyl patch. In August of that year, a judge in Oklahoma ruled that Johnson & Johnson had intentionally played down the dangers and oversold the benefits of opioids and ordered the company to pay the state $572 million.
Mr. Hunter said the ruling was the first in the country to find an opioid manufacturer liable for the harm caused by the opioid crisis in the United States.