Six Day star Iljo Keisse's B sample came back positive for cathine and for hydrochlorothiazide (HCT), according to the Belgian newspaper De Morgen. Officials have not yet formally announced the B sample results.
Keisse tested positive the end of November, after winning the Gent Six Day race.
Cathine is an appetite suppressant, decongestant and amphetamine. It is contained in the over-the-counter product Sinutab, which Keisse admitted taking.
The newspaper said the other product is hydrochlorothiazide, which is a diuretic which can also serve to mask other substances, and is on the forbidden list. Sprinter Ben Johnson lost his gold medal in the 100 metres track and field competition after testing positive for the same drug at the 1988 Seoul Olympics. (SW)