L'Equipe is reporting that the B sample taken from Katusha's Alexandre Kolobnev has also tested positive for the banned substance hydrochlorothiazide which was discovered in his urine sample taken after stage five of the Tour de France to Cap Fréhel.
Hydrochlorothiazide is a diuretic which can be used as a masking agent for performance-enhancing drugs.
Once informed of the positive test, Kolobnev left the Tour on the first rest day after initial reports suggested he had been sacked by Katusha. In a statement on his website, Kolobnev said he had no idea how the substance could have been found in his system.
With today's news that his B sample too has produced a positive test, the UCI will now refer the matter back to the Russian Cycling Federation. Katusha policy suggests that the Russian rider will now be sacked and ordered to pay a fine of five times his estimated £500,000 salary.