Briton Luke Traynor has been suspended from sport for two years for cocaine use, having served 13 months to date.
The Scot failed a UK Anti-Doping (Ukad) test after the stimulant was found in his urine at the Vitality London 10km race in May 2019.
Traynor, 26, said the cocaine trace related to out-of-competition use and was unrelated to sport performance.
Ukad accepted this and set his period of ineligibility to run from 27 May 2019 until midnight on 26 May 2021.
Ukad director of operations Pat Myhill said: "We are urging athletes to consider the significant risk that goes hand in hand with using cocaine.
"Athletes should be aware that cocaine, used out-of-competition, often stays in the system."
Traynor represented Great Britain at the World Cross-Country Championships in 2019 and the World Half Marathon Championships in 2018.
He has also represented Great Britain in the European Cross-Country Championships at under-20 and under-23 levels.
Last July, Traynor said he took "full responsibility" for his actions.
"I have made an incredibly stupid and uncharacteristic mistake and for that I am deeply sorry," he wrote on Twitter.
"This happened as a one-off and in a purely social situation with a drug I should never have taken."