Olga Yegorova, cleared to run in the world women's 5,000 metres despite failing a drugs test last month, won the final last night.
The world governing body cleared the Russian world indoor 3,000 metres champion to compete despite a positive test last month for the blood-boosting drug EPO (erythropoietin).
Before Thursday's heats British team captain and world cross country champion Paula Radcliffe and team mate Hayley Tullett held up a sign in the stands reading "EPO cheats out".
Defending champion Romanian Gabriela Szabo, who had initially threatened to boycott the race, finished eighth.