Former world junior 800 metres champion Alfred Kipketer of Kenya has been banned for two years after he missed four drugs tests within a 12-month period.
The Athletics Integrity Unit (AIU) confirmed Kipketer accepted he had committed an anti-doping rule violation for whereabouts failures, which rules him out of this year's postponed Tokyo 2020 Olympic Games.
The 24-year-old, a finalist in the 800m at the 2016 Olympics in Rio de Janeiro, missed four tests between November 2018 and September 2019.
He has been suspended from November 26 2019, the date his fourth missed test was confirmed, to November 25 of this year.
Kipketer, a member of the Kenyan team which won the gold medal in the 4x800m at the 2014 World Relays, failed to provide any explanation for three of the four failures.
He claimed he missed the third test because he had to travel to Nairobi for a family emergency, but the AIU rejected his explanation, stating he had "sufficient opportunity" to update his whereabouts to reflect his change in circumstances.
Kipketer, who also won the world youth title in 2013 and reached the final of the 800m at the 2015 World Championships, is among the more than 60 Kenyan athletes who are serving doping bans.
The AIU had provisionally suspended Kipketer in January, and he has not been able to compete since that date - although many of the events he might have featured at have been cancelled because of the coronavirus pandemic.
Notable names on the list of Kenyan runners currently banned include the 2016 Olympic women's marathon champion Jemima Sumgong and former world marathon record holder Wilson Kipsang.
The 2011, 2013 and 2015 world 1500 metres gold medallist Asbel Kiprop is also banned, as is Elijah Manangoi, who succeeded him in 2017.
Kenya is in the AIU's highest risk category for doping.