Missouri Governor Eric Greitens, who is facing impeachment over an extramarital affair and a campaign finance inquiry, has announced he will quit on Friday.
The married governor was considered a rising Republican star until allegations emerged he had photographed a naked woman without her consent.
The former Navy Seal previously dismissed the allegations as a “political witch hunt”.
The Republican is only 17 months into his first term as governor.
What did Greitens say?
“I have not broken any laws,” the 44-year-old said at Tuesday’s news conference.
“The last few months have been incredibly difficult,” he said. “This ordeal has been designed to cause an incredible amount of strain on my family.”
He concluded: “For the moment let us walk off the battlefield with our heads held high.
“We have a good and proud story to tell our children.”
What’s the campaign finance investigation?
He was charged last month with felony computer data tampering to obtain a donor list for a veterans’ charity without permission for his own political gain.
Earlier on Tuesday, a court ruling added to Mr Greitens’ problems.
Cole County Circuit Judge Jon Beetem gave the governor’s political non-profit group, New Missouri Inc, until Friday to turn over communications between it and Mr Greitens’ office.
Investigators are looking into whether his campaign illegally co-ordinated with New Missouri Inc to conceal donors by using shell companies to funnel money.
According to the Kansas City Star, Mr Greitens received $6m (£4.5m) in “dark money” for his 2016 campaign.
What was the sex scandal?
Earlier this year, it emerged that Mr Greitens had had an extramarital affair with his hairdresser.
The father-of-two presented himself as a family man during his 2016 campaign.
But a man secretly recorded his wife admitting to the affair with Mr Greitens in March 2015.
The hair stylist alleged that Mr Greitens had taken a photo of her when she was partially nude without her permission and threatened to release the images if she ever told anyone about the affair.
He said he had worked through the issue with his wife, but denied blackmailing the other woman.
Mr Greitens was indicted in February with invasion of privacy, but the charged was dropped this month.