WASHINGTON (Reuters) - U.S. Representative Jason Chaffetz, who chairs a House committee with broad investigative powers, on Wednesday announced his plans to leave Congress after the 2018 midterm elections, saying he had no intention of running for any political office. “I have no ulterior motives. I am healthy. I am confident I would continue to be re-elected by large margins. I have the full support of Speaker (Paul) Ryan to continue as Chairman of the Oversight and Government Reform Committee. That said, I have made a personal decision to return to the private sector,” Chaffetz said in a statement on Facebook.  The conservative Republican, who was first elected to the House in 2008 and represents a district in eastern Utah, gained prominence as head of the committee that was investigating Democratic presidential candidate Hillary Clinton’s use of a private email server. During the raucous 2016 presidential campaign that pitted Clinton against Trump, Chaffetz distanced himself from the Republican candidate following the public airing of a video last year in which Trump made lewd comments about women. But as Trump appeared to weather that storm and was competitive with Clinton in the homestretch to the Nov. 8 election, Chaffetz moderated his criticism of the New York real estate developer. With Trump in the White  House, Chaffetz early this year said he would use his committee chairmanship to continue investigating Clinton. But he refused to look into contacts that Trump’s national security adviser, Michael Flynn, had with a Russian official amid suspicions that Moscow played a role in influencing the U.S. elections. Flynn has since left his high-level White House job. Chaffetz, 50, had in the past considered running for a Senate seat and in announcing his retirement from the House at the end of his term next year he is leaving open that option. “I may run again for public office, but not in 2018,” Chaffetz said in his Facebook posting.        A former Chaffetz aide told Reuters the congressman may seek to run for Utah governor in 2020, though no firm decision had been made yet. 