Former world sprint champion Tyson Gay's B sample from an out-of-competition test in May has been confirmed positive for a banned substance, the U.S. Anti-Doping Agency (USADA) said on Friday, while adding he had returned another positive test.
"We can confirm that the B sample analysis of a sample collected from Mr. Gay has been completed and that the B sample analysis has confirmed the A sample findings," USADA CEO Travis Tygart said in a statement to Reuters.
Tygart also said an additional sample collected from the American sprinter had also returned "an adverse A sample finding."
A tearful Gay said in an interview on July 14 that his A sample from the out-of-competition test in May had returned a positive result for a substance he would not disclose.
The 2007 world double sprint champion then asked the B sample be tested.
He has withdrawn from the U.S. team for next month's world championships in Moscow.