South African cycling champion and former Lance Armstrong teammate, David George has tested positive for a banned substance, the South African Institute for Drug Free Sport said on Tuesday.
George, a former Olympian, tested positive for erythropoietin -- a hormone that increases the athlete's red blood cell count, helping boost oxygen carrying capacity and so improving performance.
"The blood test showed suspicious activity with regard to possible manipulation of the blood profile and a subsequent urine test came back positive for the banned EPO drug," said the institute's CEO Khalid Galant.
George is now banned from competing, pending an investigation by an independent tribunal.
George was on the US Postal Service cycling team between 1999 and 2000, at the same time as Armstrong, who has been banned for life and stripped of his seven Tour de France titles for doping offences.