Paris - Jamaican sprinter Steve Mullings has tested positive for a banned substance for the second time in his career, according to reports in the Jamaican press on Thursday.
Mullings has set the third fastest time this season for the 100 metres (9.80sec) and the season's fifth best time for the 200m (20.11).
But his bid to compete in both events at the upcoming world athletics championships in Daegu, South Korea could be compromised by reports which claim he tested positive for a masking agent at the Jamaican national championships at the end of June.
If confirmed, the test could bring an end to the career of Mullings, who served a two-year ban for doping in 2004-2006.
Mullings, 28, has a world title from 2009 when he helped the men's Jamaican 4x100m relay team to victory in Berlin.