New Scientist said:
It was a heavy blow for Belarus as Ivan Tsikhan, their champion hammer thrower, was withdrawn from the Olympic Games last week after he was found to have used banned substances to win silver in Athens eight years ago.
Drug cheats develop ever more sophisticated ways of avoiding detection while anti-doping authorities hurry to catch up. This game of cat and mouse gives the International Olympics Committee (IOC) reason to maintain an eight-year statute of limitations on drug-related offences.
However, anti-doping technologies may be so far behind that this statute could be extended to 14 years, says Andy Parkinson, chief executive of UK Anti-Doping.