The test took place September 7 following stage 18 of the Vuelta, a race which Froome won overall with Nibali finishing in second place. Froome and Team Sky are currently in the process of gathering their defence, and although the rider has not been suspended, he could face a ban if the UCI fail to accept his case.
The WADA threshold for salbutamol is 1,000ng/ml, but according to Team Sky Froome's reading was double that figure. According to the UCI, Team Sky were notified of the finding on September 20, the day he finished third in the elite men's time trial at the UCI World Championships in Bergen.
"Today the cycling world received bad news," Nibali said in a comment posted on Twitter. "If this is confirmed, no one will be able to give me the possibility to go on the top of the podium in Madrid. I'm sure time will give us the right answers."
Nibali revealed he also suffers with asthma but suggested rain during the final stages of the Vuelta meant there was no need to use an asthma inhaler that contained salbutamol.
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