US Figure Skating is holding its National Championships and Olympic trials this week ©US Figure Skating

Vast numbers of people at the official US Figure Skating hotel for this week's Olympic trials have been spotted without masks in breach of the COVID-19 protocols in operation at the event, according to reports.

USA Today reported seeing numerous maskless people at the hotel in Nashville, where many athletes, coaches, judges and officials are staying.

Masks and COVID-19 vaccination cards or tests are mandatory for all fans, while all three are required for members of the media at the trials, set to take place until Sunday (January 9) and which fans and media are permitted to attend.

A member of the hotel staff said he was surprised by the number of people who said they were involved with the event who came in maskless, USA Today reported.

Other similar competitions, including US Speedskating's Olympic trials and Canada's Olympic figure skating trials, are due to be held without spectators and members of the media because of renewed concerns over the spread of COVID-19 following the emergence of the Omicron variant.

Reigning national pairs champions Alexa Knierim and Brandon Frazier have withdrawn from the event, doubling as the National Championships, after the latter athlete tested positive for COVID-19.

Knierim and Frazier could still be selected to the team for the 2022 Winter Olympic Games in Beijing despite missing out on the competition.

"Although my symptoms are pretty bad, nothing sucks more than not being able to compete," Frazier said in a video posted on Instagram.

The Beijing 2022 Winter Olympics open on February 4.