Marion Jones cannot compete at the Zurich Golden League meeting because of doping claims against her, organisers have confirmed.
Fellow American Michelle Collins has also been told she is not welcome at the 6 August event in Switzerland.
Event spokesman Nicolas Russi told Reuters: "We don't want athletes involved in doping cases."
Jones denies the allegations, while Collins was charged offences in June despite never failing a test.
Russi said: "Our general attitude was that we want to keep the credibility of the event."
Jones is under investigation by the US Anti-Doping Agency after being accused by her ex-husband CJ Hunter of using drugs at the 2000 Sydney Games.
She has strongly denied ever using banned substances.
Jones claimed three gold medals in Sydney, winning the 100 and 200m as well as gold in the 4x400m relay.
Collins was the 2003 world indoor champion at 200m.