Alberto Contador has called suspicions that riders are using secret motors in their bikes "a joke ... something from science fiction", but the UCI is taking every step to ensure that so-called mechanical doping is not taking place at the Giro d'Italia.
It's a rumour that first began when Fabian Cancellara rode away from Tom Boonen on the Kapelmuur in the Tour of Flanders in 2010, and although no evidence was found even after the UCI instituted bike checks, the issue continues to simmer.
In this video, the bike of race leader Contador is put through a series of checks by the officials, who even pull out the bottom bracket to find - nothing.
Should the UCI find evidence of motors, it now has recourse with rules introduced this year to punish riders with a six month ban for rider and team, and a 1 million Swiss Franc fine.
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