NEW YORK CITY-- ESPN is reporting that Tyson Gay has been notified that he tested positive for a banned substance.
The U.S. Anti-Doping Agency is responsible for testing athletes for a list of substances.
It is currently not known what substance Gay is alleged to have used.
Gay is expected to pull out of the world championships, according to ESPN.
Tyson Gay is a former University of Arkansas track athlete, as well as the current record holder in the 100-meter competition.
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