Former triple Olympic champion Marion Jones was cleared of doping after her 'B' sample tested negative for the blood-boosting drug EPO.
Jones's initial sample had tested positive for erythropoietin (EPO) at the US Championships in Indianapolis in June. The 30-year-old could have faced a two-year ban from the sport had the second sample tested positive.
"Marion Jones was informed by the USADA (US Anti-Doping Agency) that her 'B' sample urine test was negative. She has been cleared of doping allegations," Jones's attorneys Howard Jacobs and Rich Nichols said.
"I am absolutely ecstatic," Jones said.
"I have always maintained that I have never ever taken performance-enhancing drugs, and I am pleased that a scientific process has now demonstrated that fact.
"I am anxious to get back on the track."
Jones could conceivably run in the IAAF World Cup of Athletics in Athens on Sept. 16-17. Jones's coach Steve Riddick said he would prepare her to run in the Athens meeting if she wanted to compete.
Jones has three of the six fastest times in the world this year with a best of 10.91 seconds.