TIMELINE: Drugs cheats who dragged sport into gutter
1988
Ben Johnson wins Olympic 100m title in Seoul but Canadian is stripped of title after anabolic steroid Stanozol is detected in his urine sample.
2003
Dwain Chambers receives two-year ban after testing positive for THG, a banned performance-enhancing drug. Briton is stripped of the 100m European title and record he achieved in 2002.
2007
International Olympic Committee strips Marion Jones of five Olympic medals (three gold, two bronze) she won at 2000 Olympics after American admits steroid use.
2013
Former 100m and 200m world champion Tyson Gay, left, tests positive for a banned anabolic steroid and the USA athlete is banned for 12 months. In the same year, Jamaican Asafa Powell, the all-time fourth quickest sprinter and former 100m world record holder, is suspended for 18 months, which was reduced to six months on appeal.
2015
Russian heptathlete Tatyana Chernova tests positive for
a banned steroid after a sample that was collected in 2009 is re-tested. Britain’s Jessica Ennis-Hill is then awarded 2011 world title as a result. In November Russian Athletics Federation are suspended after a World Anti-Doping Agency (Wada) report reveals widespread doping in the country and they receive a partial ban from the 2016 Rio Olympics.