Allegations of widespread doping in athletics are "sensationalist and confusing", according to the sport's governing body.
With one year to go until the Rio Olympics, BBC Sport assesses Team GB's chances of surpassing their record medal tally.
- Clarke confident of hitting Rio peak
- Green & Levine added to GB squad for Beijing
- Zero tolerance to doping, says IOC
- Rooney wins Worlds omission appeal
- Turner backs tough doping penalties
- Doping claims sadden hurdles champion Child
- Minichiello queries lack of action
- Coe wants 'robust' doping response
- Rudisha suffers first loss in Kenya
- No wrongdoing by Farah - UK Athletics
- Briton Waite fails in Worlds appeal
- Rutherford wins Stockholm long jump
- 'I lost all honour in gender case'
- Wales Bundy-Davies targets Worlds medal
- Ennis-Hill in GB squad for Worlds
- Chand wins appeal over hormone ban
Athletics Video & Audio
- Watch video Dominant Rutherford wins in Stockholm
- Watch video Fraser-Pryce eases to 100m victory
- Watch video 'I run to inspire my daughter'
- Watch video Asher-Smith makes 100m history
- Watch video Proctor sets British long jump record
- Watch video Amos beats Rudisha in men's 800m
- Watch video GB men clinch 4x100m relay victory
- Watch video Bolt wins 100m in 9.87 seconds
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World Athletics Championships
Details of BBC Sport's live television and radio coverage of the World Championships in Beijing from 22-30 August.