Sprinter Ben Johnson of Canada poses after running next to a scroll petition laid out on the track at the Seoul Olympic Stadium in Seoul September 24, 2013. Johnson, who tested positive for a banned substance after winning the men's 100-meter final at the Seoul Olympics in 1988, visited the scene of the infamous competition on Tuesday, the 25th anniversary of the race. Johnson visited Seoul as a part of an international anti-doping campaign, "Choose the Right Track", organised by an Australian sports apparel company, reported local media. REUTERS/Lee Jae-Won (SOUTH KOREA - Tags: SPORT OLYMPICS ATHLETICS)