WADA, which manages anti-doping efforts for the IOC worldwide, has just admitted, apparently, that about 23 Chinese Olympic swimmers (3/4 of the team) tested positive for "low levels" of trimetazidine, an angina medication which also changes the way the body uses glucose and fat for fuel. Now WADA has apparently bought the explanation that it was "contamination" (doesn't everybody occasionally get angina medications in their groceries?), but if I approach this from a statistical point of view, when I see everybody having similar low levels of a drug that has a half life in the body of about eight hours, my best guess is that all of the team was given a much higher dose of the drug a few days earlier. On purpose.
Worth noting as well is that this is not something, given different food preferences, that can be explained by "oopsie, something fell into the fried rice in the cafeteria." So what do we have here? In my view, what we have is a partial resurrection of the Communist bloc flouting of IOC doping rules.