Johannesburg - Mountain biker Philip Jansen van Vuuren has been provisionally suspended after testing positive for a banned substance, Cycling South Africa (CSA) announced on Tuesday.
"Jansen van Vuuren returned an adverse analytical finding in an in-competition test conducted by the South African Institute for Drug-Free Sport (SAIDS) in July," CSA said in a statement.
"The sample was collected at the South African mountain bike cross-country championships held on July 20 and confirmed the presence of the anabolic agent clenbuterol (anabolic steroid).
"Philip is therefore provisionally suspended with immediate effect from competing in any event."
CSA reiterated its zero-tolerance approach to doping in sport and said the Saids process would now take its course.