Sportshour

For years there had been rumours. But they were just that - rumours. Then in 2015, a BBC documentary accused one of the world's top athletics coaches of being involved in widespread doping. This week, Alberto Salazar was banned from the sport for four years after an investigation by the US anti-doping agency. Salazar runs the Nike Oregon Project, which has been home to some of the world’s leading athletes, including, until two years ago, Britain’s four-time Olympic champion Mo Farah. Mark Daly, an investigative journalist for the BBC, has been following this story for more than four years. He tells Caroline the process behind making the documentary and how he got key witnesses to speak up.We’re riding the waves with one of the top names in surfing, Mercedes Maidana. In her own words, she was "truly living the dream, travelling the world chasing waves, until one incident that changed everything". In 2014, Mercedes suffered a head injury at a competition in the United States. She lost her career, sponsorship,