Julius Yego wins javelin but Kenyan pair's positive tests cast shadow

• Joyce Zakary and Koki Manunga revealed to have failed pre-competition tests • New world champion Yego insists he is competing clean On the day that two Kenyan athletes became the first to test positive at a world championships overshadowed by the drugs issue the country's first ever javelin gold medallist insisted he was competing clean. Julius Yego recorded 92.72m in the Bird's Nest, within six metres of Jan Zelezny's current world record set in 1996, and added another gold medal to Kenya...