How serious is corruption in sport?

Allegations of widespread doping in Russian athletics are the latest scandal to damage the world of sport.

The World Anti-Doping Agency has published a scathing report into widespread doping in the sport of athletics.

The report, in particular, signalled out Russia, which it said should be banned from athletics competition for running a "state-supported" doping programme.

Now, there are calls for the Russian athletics federation to be banned - and its athletes barred from next year's Olympic Games in Rio de Janeiro.

The latest scandal follows others in world football, rugby league, cycling and other sports.