Olympics-Athletics-Seeing's not believing - how doping has tainted athletics

FILE PHOTO: Ethiopia's Abeba Aregawi (2nd R) wins ahead of Turkey's Gamze Bulut (R) and Russia's Tatyana Tomashova (L) in their women's 1500m semi-final during the London 2012 Olympic Games at the Olympic Stadium August 8, 2012. REUTERS/Lucy Nicholson /File Photo

TOKYO (Reuters) - There are a few worthy contenders for the "dirtiest race in history" title but the 2012 Olympic women's 1,500 metres probably takes the gold medal for not only the brazen nature of the cheating, but the sheer depth of it.

Athletics is by no means the only Olympic sport to be badly hit by doping cases over the last few decades but due to its premier profile and multiplied by the huge scale of Russian doping and evasion, it has endured a grim time.