South Korean judoka An Ba-ul has been banned for six months for doctoring his community service records.
The punishment from the Korea Judo Association (KJA) means the Rio 2016 Olympic silver medallist could struggle to qualify for the Tokyo 2020 Games.
Olympic medallists and Asian Games champions in South Korea are exempt from the country's compulsory military service for men, which demands two years of service in the armed forces before the age of 28.
Instead, they must carry out 544 hours of sports-related community service over 34 months but 24-year-old An has been found to have falsified his records.
According to Yonhap, his file showed that he had carried out community service on a day when he was training in Jincheon.
An won Olympic under-66 kilograms silver in Rio and also won the world title in the weight class in 2015 and the Asian Games gold last year.
He will now miss a national team selection camp which begins on March 12 as well as this year's World Championships in Tokyo in August.
With the World Championships the biggest qualifying event for the Tokyo Olympic tournament, his place at the Games in 2020 is under threat.
Yonhap said the KJA had been considering a one-year ban but reduced it to six months after taking An's achievements into account.
It was confirmed that he has completed 365.5 hours of his community service.
"I'm deeply sorry to people who were offended by my reckless behavior," An said, according to Yonhap.
"After the National Training Centre was moved to Jincheon, North Chungcheong Province, I didn't want my training to be affected by my long commute to the community service location, and I made a careless decision."
Footballer Jang Hyun-soo was banned for life from the South Korean national team in November after also being found guilty of fake community service records.