Organizers of the Beijing Half Marathon announced on Monday that they were investigating after footage widely shared online showed three African runners deliberately allowing China's He Jie to win.
Video clips from Sunday's race showed Kenyans Robert Ketel and Willy Mnangat, Ethiopia's Dejen Haile and home runner Hee approaching the finish line.
The three African runners can be seen pointing towards the finish line and waving forward while appearing to slow down.
The 2023 Asian Games marathon gold medalist won by one second.
The four remained close together throughout the 13-mile (about 21 km) course, the broadcaster said.
“We are conducting an investigation and will make the results public as soon as we know them,” a Beijing sports bureau official who requested anonymity told AFP.
The event's organizer, the Beijing Sports Competition Management and International Exchange Center, also said an investigation had been launched.
The incident attracted a lot of attention on Chinese social media site Weibo, with some users criticizing the outcome as “embarrassing”.
“This will definitely be the most embarrassing championship in He Jie's career,” one person wrote.
“For such a major organizer and such a prestigious event, this is a truly shameful display of sportsmanship,” the post said.
Athletics' international body said it was “aware” of the online footage and the investigation into it.
“Sporting integrity is our top priority at the World Athletics Championships, but as the investigation is ongoing we are unable to comment further,” director of communications Jamie Foxx told AFP.
Long-distance running has experienced a boom among China's middle class in recent years, but fraud and poor organization abound.
In 2018, 258 runners were found to have cheated at a half marathon in the southern city of Shenzhen, including one who took a short cut.
Traffic cameras captured them running through the trees to take part in another part of the race.
In 2019, a woman was photographed riding a green rental bicycle at the Xuzhou International Marathon in eastern China.
She was ordered off the bike by race officials, but then got back on the bike.
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