Al Jazeera’s Investigative Unit takes viewers inside the secret world of sports doping – and raises questions whether some of the biggest names in American sport are using banned substances. Working with former British athlete Liam Collins as an undercover reporter, the programme penetrates the shadowy world of doctors, pharmacists and medical professionals who provide drugs and guidance to athletes trying to cheat the system. The Dark Side begins in the Bahamas, where 37-year-old Collins is testing out his cover story. In order to get one last shot at Olympic glory in Rio, he is willing to dope himself up. The investigation takes Collins to Vancouver, where he meets cutting-edge doping chemists and doctors. One provides him with a mountain of banded drugs. Collins finally exposes a Texas-based pharmacist who alleges that major baseball and American football players are linked to banned substances.