WASHINGTON — The White House will pull the nomination of Jeffrey Byard to be the head of the Federal Emergency Management Agency after a federal inquiry into a possible barroom altercation involving Mr. Byard prompted concern in Congress and the White House, according to federal officials familiar with the investigation.
While the F.B.I. determined that the allegations facing Mr. Byard were unsubstantiated, the White House is expected to nominate the current acting administrator of FEMA, Peter T. Gaynor, to lead the agency instead. That move is expected before the end of the month, officials said.
President Trump said in February that he would nominate Mr. Byard after Brock Long resigned as the chief of the agency. Mr. Long left after the inspector general of the Department of Homeland Security, which oversees FEMA, found he had improperly used government vehicles to travel between work and his home in North Carolina.
Senator Ron Johnson of Wisconsin, who leads the Senate Homeland Security Committee, confirmed to Politico last week that Mr. Byard’s nomination had been delayed. “There were some issues raised that are being investigated and that’s all I’ll say about it,” Mr. Johnson said.
The inquiry into the allegation of Mr. Byard’s inappropriate conduct began after the committee held a hearing and voted in June to send his nomination to the full Senate for confirmation.
A spokeswoman for the Department of Homeland Security referred requests for comment to FEMA. A spokeswoman for FEMA said the agency was not permitted to comment on accusations that involved a personal matter that supposedly occurred before Mr. Byard joined the agency two years ago as associate administrator of the Office of Response and Recovery.
The timing of the alleged episode, which officials say took place in a bar, remains unclear.
FEMA, the agency tasked with providing emergency assistance to communities affected by natural disasters, has not had a confirmed leader since Mr. Long’s resignation. In the past two years, the agency has faced intense criticism over its handling of Hurricane Maria’s devastation of Puerto Rico, which caused an estimated 3,000 deaths and left thousands without electricity.
Last week, a former top administrator of agency was arrested in a major federal corruption investigation that found that the official had taken bribes from the president of a company that secured $1.8 billion in federal contracts to repair Puerto Rico’s shredded electrical grid after the hurricane.
As a top official at the agency, Mr. Byard has had a direct hand in providing resources to communities hit by hurricanes and wildfires in the United States.
The impending withdrawal of his nomination comes in the middle of an already destructive hurricane season.
Mr. Gaynor, whose intended nomination was first reported by Axios, had wide support in the Department of Homeland Security and has led the agency through Hurricane Dorian, which just missed the Virgin Islands and Puerto Rico but devastated the Bahamas. The hurricane, which reached a Category 5 strength, killed at least 50 people in the Bahamas, a death toll that is expected to increase drastically.
A retired Marine, Mr. Gaynor is also overseeing an overhaul of the government-subsidized flood insurance program, which is expected to raise rates on more expensive properties and those in higher-risk areas.
The change is only the latest leadership shake-up at the Department of Homeland Security, responsible for overseeing the country’s borders, immigration policy and addressing domestic terrorism and cybersecurity threats in addition to disaster relief.
Officials leading each agency overseeing immigration or border security — United States Citizenship and Immigration Services, Immigration and Customs Enforcement and Customs and Border Protection — are serving in an acting capacity.
Kevin K. McAleenan, the acting secretary of the Department of Homeland Security, has yet to be nominated.
And on Tuesday, the White House fired the agency’s general counsel, John Mitnick.