Organisers of the Beijing half marathon are investigating allegations that three African athletes deliberately allowed China's star runner He Jie to win Sunday's race.
Footage appeared, external to show Kenya's Robert Keter and Willy Mnangat and Ethiopia's Dejene Hailu pointing to the line and slowing down before waving.
He, 25, finished one second ahead of the trio, who tied for second place.
The result was criticised by some Chinese social media users.
A spokesperson at the Beijing Sports Bureau told AFP they were investigating the incident, adding: "We will announce the results to the public once they are available."
Xstep, a Chinese sports brand who sponsored the event and have a contract with He, told Chinese state-owned The Paper, external: "The situation is still being confirmed and verified by multiple parties. Further information will be communicated as soon as possible."
He, 25, won marathon gold at the 2023 Asian Games in Hangzhou and is his country's record holder in the event.
None of the runners have commented on the incident.
A statement from World Athletics to BBC Sport said: "We are aware of the footage circulating online from the Beijing half marathon this weekend and understand an investigation is currently being conducted by the relevant local authorities.
"The integrity of our sport is the highest priority at World Athletics, while this investigation is ongoing we are unable to provide further comment."
Users of Chinese social media site Weibo have posted about the race, with a comment saying "this is no doubt the most embarrassing title of He Jie's career" receiving more than 1,000 likes.
Another post added: "With such a major organiser and such a well-known event, this really pushes sportsmanship to the ground in shame."
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