The 23-year-old Eritrean-born athlete became a Swedish citizen in 2018 and won the nation's first men's gold in the competition.

A doping test from November, prior to the Championships, showed an unauthorised substance according to Swedish national broadcaster, SVT. 

Stefan Olsson of the Swedish Athletics Association said the test was performed in Ethiopia's capital of Addis Ababa and then transported to a laboratory in Lausanne in Switzerland.

"We in Swedish Athletics feel great seriousness and a great sadness," said Johan Storåkers, Swedish Athletics Association general.

"We are also determined, with our colleagues in athletics, to continue the fight for clean sport."

Pending further investigation, he has been suspended from the national team and has until February 14 to ask for a B-sample to be analysed and until February 21 to appeal the decision.

"He is perplexed, desperate and sad, he says he does not understand how it happened," said David Fridell of Fsiha's athletics club, Spårvägen.

Silver medallist from Lisbon, Turkey's Aras Kaya has said in an interview with Swedish newspaper Aftonbladet, “I'm disappointed in the guy. 

"He cheated when everyone else was clean."

The news comes days after Albania's Klodiana Shala and Turkey's Gülcan Mıngır were given provisional suspensions after their tests from London 2012 came back positive in retesting.