An independent report commissioned by the World Anti-Doping Agency says Russia operated a state-sponsored doping programme at the Sochi Winter Olympics in 2014.

Russian track-and-field athletes have already been suspended from international competitions because of a doping scandal, but the findings of this latest investigation could prompt a ban on all Russian sportsmen and women from the Rio Olympics.

Russia's athletics federation is challenging the suspension of its athletes from Rio. Hammer thrower Sergey Litvinov told our Moscow correspondent, Steve Rosenberg, what the ban means for him.