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.