Time and time again, when someone gets busted for doping, I hear talk of "Well maybe they were sabotaged, and someone tainted their food/drink/supplements." Alberto Salazar was apparently paranoid about this thing, to the point it was alleged he tested supplements on his son to see if a false positive could be obtained.
It all sounds intriguing in a cloak and dagger, cut throat competition sort of way, but has this ever been proven to have occurred? Now I don't mean cases like Tanya Harding, where a competitor was assaulted. I mean, has there even been a proven instance where one competitor intentionally tainted another's food or drink to obtain a false positive so they'd be knocked out of competition?