The South African cycling champion and former Lance Armstrong team-mate David George has tested positive for a banned substance.
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.
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.
