Ben Johnson (Canada). Stripped of his 100 metres gold medal at the 1988 Seoul Olympics after testing positive for banned steroids. Still the biggest scandal to hit the Olympic Games.
Linford Christie (Britain). At 32, the oldest man to win gold in the 100 metres with victory at the 1992 Barcelona Olympics. Seven years later, in semi-retirement, tested positive for the steroid nandrolone.
Dennis Mitchell (US). The American, who won gold as part of the US 4×100 metres relay team at the 1992 Barcelona Olympics, was banned for two years in 1998 for excessive levels of the male sex hormone testosterone.
Dwain Chambers (Britain). Finished fourth in the 100 final at the 2000 Sydney Olympics but was banned for two years in 2003 after testing positive for the designer steroid THG in the BALCO laborary scandal.
Tim Montgomery (US). Also implicated in the doping scandal that engulfed the San Francisco laboratory. The American set a 100 metres world record of 9.78 in 2002 but later admitted to doping at the 2000 Sydney Olympics.
Marion Jones (US). Montgomery’s partner and the biggest victim of the BALCO scandal, Jones became the first woman to five track and field medals at a single Olympics at Sydney 2000 After years of denial, she confessed to being a drugs cheat and was jailed for lying to federal investigators.
Kelli White (US). Another BALCO victim who admitted to using a cocktail of drugs after winning the 100-200 double at the 2003 Paris world championships.
Justin Gatlin (US). The American, who won gold in the 100 at the Athens Olympics, has served two doping bans, including four years for excessive levels of testosterone. Won bronze at the 2012 London Olympics.
Veronica Campbell-Brown (Jamaica). Twice Olympic 200 metres champion who is currently suspended after testing positive for a banned diuretic at a meeting in May this year.
Sherone Simpson (Jamaica). Gold medalist at the 2004 Olympics in Athens and a silver medalist last year in London as part of Jamaica’s 4×100 metres relay teams, Simpson tested positive for the banned stimulant oxilophrine at last month’s Jamaican athletics championships.
Tyson Gay (US). Completed a memorable sweep of sprint tiltes at the 2007 world championships in Osaka when he won the 100 and 200 metres and was part of America’s triumphant 4×100 metres relay team. Tested positive for a unidentified substance in an out-of-competition test in May this year.
Asafa Powell (Jamaica). Held the 100 world record between 2005 and 2008. Tested positive for oxilophrine at the national championships last month.
Katerina Thanou/Kostas Kenteris (Greece). Thanou (100 metres silver medallist in Sydney) and her Greek team mate Costas Kenteris (Sydney 200 metres champion) were accused of faking a motorcycle crash just before the 2004 Athens Olympics to skip a dope test.
Merlene Ottey (Slovenia). Jamaican-born sprinter who won world 200 titles but was banned from the 1999 Seville world athletics championships after a positive test for nandrolone. Later cleared by the International Association of Athletics Federations.
Katrin Krabbe (Germany). Double sprint champion at the 1991 world championships in Tokyo who never competed at an Olympics after a ban for the anabolic agent clenbuterol.