US President Donald Trump’s chief of staff Mark Meadows has been diagnosed with COVID-19, sources have told reporters.
Two senior administration officials have confirmed Mr Meadows has tested positive for the virus.
Mr Meadows accompanied Mr Trump at rallies across the country during the final days of the election campaign.
He last appeared in public early Wednesday morning without a mask as Mr Trump falsely declared victory in the vote count.
The officials offered no details on when the chief of staff came down with the virus or his current condition.
The news of another infection among White House staff came as the country recorded its third consecutive day of more than 100,000 new cases of the virus, with almost 130,000 positive tests.
The virus has killed more than 236,000 Americans so far this year.
Mr Trump, first lady Melania Trump and son Barron tested positive for the virus early last month.
Mr Trump spent three days in hospital and returned to the campaign trial when he was no longer infectious.
West Wing epidemic
At least two dozen others tested positive after a large gathering announcing the nomination of now-Justice Amy Coney Barrett to the Supreme Court.
Almost two weeks ago, Vice-President Mike Pence’s chief of staff Marc Short and other aides tested positive for the virus.
White House chief of staff Mark Meadows on the sideline of a medical press conference outdoors
Mr Meadows had been one of the close aides around Mr Trump when the president came down with the virus more than a month ago, but he was tested daily and maintained his regular work schedule.
Mr Meadows was at a White House election night party attended by dozens of Trump loyalists.
COVID-19 cases in the US have increased more than 50 per cent in the past two weeks.
According to an AP analysis of data from John Hopkins University, the seven-day rolling average for daily new cases rose from 61,166 on October 22 to 94,625 on November 5.