Kenya’s 2017 world 1500 metres champion Elijah Manangoi has been banned for two-years after missing a series of drugs tests.
It means he will miss next year’s re-arranged Olympic Games in Japan.
The 27-year-old was provisionally suspended by the Athletics Integrity Unit (AIU) in July after missing three out-of-competition drugs tests in 2019 between July and December.
The AIU rejected a plea from Manangoi for a reduced sentence which could have allowed him to qualify for Tokyo 2020.
Manangoi was unable to defend his title at the 2019 World Championships in Doha due to injury.
Since July 2017, he is the only man to defeat Kenyan Timothy Cheruiyot in the 1500m, doing so five times.
Cheruiyot won the 2019 world title and is the Olympic favourite.
Manangoi's ban has been backdated until December 22 in 2019, the date of his third missed drugs test.
The ruling means "disqualification of all competitive results obtained by the athlete since 22 December 2019 with all resulting consequences, including the forfeiture of any titles, awards, medals, points prizes and appearance money," the AIU said in a statement.
Manangoi had blamed his first missed test on a delayed flight back from Europe, the second on heavy traffic when he was returning home from a night shift working for the Kenyan police and the third on the fact he was in Austria receiving treatment for an injury.
Besides winning the world title, Manangoi also claimed the 1500m gold medal at the 2018 Commonwealth Games in the Gold Coast.
The same year he won the title at the African Championships in Asaba in Nigeria.
Manangoi has only competed once this year, in an exhibition 2000s race in the "Impossible Games" where a five-man squad led by Cheruiyot competed remotely in Nairobi against another five-man team of Norwegian athletes led by Jakob Ingebrigtsen, who ran in Bislett Stadium in Oslo.
Manangoi joins a long list of top Kenyan runners banned for doping offences.
Jemima Sumgong was banned after winning the marathon at the 2016 Olympic Games in Rio de Janeiro following a positive drugs test for erythropoietin (EPO).
Asbel Kiprop, a 2008 Olympic 1500m gold medallist and a three-time world champion, was banned for four years after testing positive for EPO in November 2017.
Last month, Daniel Wanjiru, the 2017 London Marathon winner, was banned for four years over abnormalities in his athlete biological passport.
In July, Wilson Kipsang, a former marathon world-record holder, was banned for four years after missing drug tests.
Manangoi also takes his place alongside a growing number of top international athletes to have been suspended for missing drugs tests or whereabouts failures.
Last month the United States' world 100m champion Christian Coleman was banned for two-years after missing three drugs tests.
To read the full AIU decision click here.