Questions are being asked after a Chinese speed skater appeared to flick a marker underneath the skate of her Canadian opponent, which some believe caused her to fall during a chaotic day on the ice in Beijing on Monday.
A viral clip of the blink-and-you'll-miss-it moment was viewed more than three million times within hours of being posted on Reddit. It was later deleted, then re-posted on the social media site.
In the video, Kexin Fan, 28, can be seen reaching over the leg of another competitor as a marker is flicked towards the left skate of Alyson Charles, 23. Charles then falls over.
"'Sportsmanship' shown by the Chinese skater in the Beijing Olympics," the original poster titled the video.
"This was some slick s**t, it took me like 10 watches to figure out what happened," one user commented.
Others on social media raised eyebrows at the incident and Canadian sports journalist Rob Williams penned an article for Daily Hive questioning if anything untoward had happened.
"Sabotage or incidental contact?" he tweeted. "The slow motion replay from this morning's short track speed skating event looks suspect."
The incident occurred during the Group One Women's 500m Short Track Speed Skating quarterfinals at Capital Indoor Stadium, the first race of the night.
In a twist, however, it was Charles' Canadian teammate Florence Brunelle, 18, who was penalised for tripping both Charles and Fan.
Brunelle had earlier made an illegal late inside pass, creating contact with Fan, earning her second penalty of the Games after another in the mixed relay two days earlier that resulted in Canada being bumped down the standings.
"That's sport," a tearful Brunelle told The Globe and Mail after the race. "Through making mistakes, I'll learn. I'll arrive more ready for other competitions having lived what I'm going through."
Italy's Arianna Valcepina, 27, and Canada's Kim Boutin, 27, qualified in the race while Charles was allowed to advance to the semi-final, where she finished fourth. She finished third in the B final and eighth overall.
Boutin, the world record holder in the event, went on to win the bronze medal with a time of 42.724 seconds, with Italian Arianna Fontana, 31, taking gold with a time of 42.488 and Suzanne Schulting, 24, of the Netherlands claiming silver in 42.559.
Fan has previously been involved in on-ice controversy. At the 2018 Winter Olympics in Korea, the Chinese team was disqualified from the Women's 3000m Team Relay final after Fan crossed over and impeded a Korean skater.
Canada was also disqualified in that event.
At the time, the International Skating Union took the unusual step of releasing images that were reviewed by referees resulting in penalties for China and Canada.
"During China's final relay exchange, the activate Chinese skater (Kexin Fan) drastically changed lane from the outside to the inside, impeding the active Korean skater (Choi Min-jeong)," the ISU said.