Rudy Giuliani, incumbent President Donald Trump's personal lawyer, has tested positive for COVID. Trump revealed the diagnosis through social media, BBC News reported Monday.

The former New York City mayor, who has been spearheading the Trump campaign's legal challenges to the 2020 election results, is the latest in Trump's inner circle to get the virus.

Giuliani repeatedly claimed he has proof of widespread voter fraud but he has failed to show evidence.

He looked well moments before Trump tweeted about his condition while sharing unfounded claims of election irregularities during a 10-minute interview with Fox News.

"Rudy Giuliani, by far the greatest mayor in the history of NYC, who's been working tirelessly exposing the most corrupt election (by far!) in the history of the USA, has tested positive for the China Virus," The New York Times quoted Trump saying on Twitter. "Get better soon Rudy, we will carry on!" Trump added.

The 76-year old Giuliani was admitted to Georgetown University Medical Center on Sunday, sources with knowledge of his condition said.

His son, Andrew, who is on the White House staff and tested positive for the disease in November, said on Twitter that his father was "getting great care and feeling well."

Giuliani has been seen often without any face covering. He was spotted in Atlanta on Thursday walking without a face mask and chatting with people whose faces were also uncovered. Other members of his legal team have been exposed.

Almost 14.7 million people have been infected with coronavirus in the U.S., based on data by Johns Hopkins University, and 281,235 have died - the highest of any country.