Does the world of sport need a Mr Clean to fix it? The constant drip of doping allegations, bribery and corruption - that have, one way or another, dogged the sporting world - have tainted it. Zeinab Badawi speaks to former British Olympic champion Sebastian Coe, who set twelve world records during his athletics career on the track and went on to hold many roles in various sporting organisations. Now he wants to become the president of the International Association of Athletics Federations, the IAAF. What more can be done help clean up sport?