WASHINGTON, Oct 12 (Reuters) - The risk of COVID-19 hung over Monday's opening of Amy Coney Barrett's U.S. Supreme Court confirmation hearings, with the Senate hearing room including at least one lawmaker who tested positive for the disease as well as the judge's seven children.

President Donald Trump formally nominated Barrett at a packed Sept. 26 White House ceremony. Less than a week later, he and a spate of close advisers and aides tested positive for the respiratory disease that has killed more than 214,000 Americans.

Republican Senator Mike Lee, one of two members of the Senate Judiciary Committee to test positive, attended the hearing in person on Monday.

"I feel great!" Lee, wearing a blue surgical mask, told reporters as he entered the hearing room on Monday, nine days after disclosing he had tested positive for the virus, which normally would prompt a 10- to 14-day quarantine.

Lee took his mask off to deliver his opening statement, to the audience of about a dozen of his fellow senators, some of them among the chamber's oldest members - as well as Barrett's husband and children.

The children left about 90 minutes into the hearing.

Democrats and many public health experts have assailed the Republican Trump for his handling of a pandemic that has killed more people in the United States than any other country.

His nomination of Barrett to a vacancy created by the death last month of liberal icon Ruth Bader Ginsburg just weeks before an election enraged Democrats, still furious about Senate Republicans' refusal to consider a nominee from Democratic President Barack Obama some 10 months before the 2016 election.

The decision to go forward with hearings as COVID-19 spreads among top Trump allies further angered Senate Democrats.

"We should not be holding this hearing when it's plainly unsafe," said Democratic Senator Patrick Leahy, who participated via computer linkup. But Republicans, who hold a majority in the Senate and have the votes to approve the nominee, pressed ahead.

Senator Lindsey Graham, the committee's Republican chairman and a close Trump ally, argued sufficient precautions had been taken.

"We've set up a room in a fashion where we can safely do our business," a masked Graham noted.

The other Republican committee member to test positive after the Sept. 26 event, Thom Tillis, was not in the hearing room. He had announced that he would be among senators participating remotely, at least on Monday.

Barrett was seen removing her mask at least once while Lee was speaking, as she took a sip of water.

The vast hearing room in the Hart Senate Office Building is the largest in the sprawling Capitol complex, where 20,000 people work and thousands more visit on a normal, non-pandemic weekday.

Barrett's children had also attended the Sept. 26 event.

The Trinity School, a private school in South Bend, Indiana, that they attend, reported less than two weeks after the Rose Garden ceremony that at least two students and a teacher had tested positive.

The Washington Post reported that Barrett tested positive for the coronavirus earlier this year but has since recovered, citing three officials familiar with her diagnosis. The White House has declined comment.