(SportsNetwork.com) - Tyson Gay already returned his 2012 Olympic silver medal after testing positive for a banned substance and now his teammates must do the same.

The International Olympic Committee on Wednesday officially disqualified the United States from the men's 4x100-meter relay at the London Olympics over Gay's positive test.

Gay, the American 100-meter record holder, accepted a one-year suspension last May after admitting he failed an out-of-competition doping test in 2013.

He also accepted a loss of results dating to July 15, 2012 -- about a month before Gay, Trell Kimmons, Justin Gatlin and Ryan Bailey finished behind Usain Bolt and Jamaica in the 400-meter race. Jeffery Demps and Darvis Patton also will give back the medals they won for helping the U.S. qualify for the final.

Gay returned his medal after he was suspended last year. On Wednesday, a U.S. Olympic Committee spokesman called the IOC's decision to strip the remaining medals "expected."

"We will begin efforts to have the medals returned, and support all measures to protect clean athletes," Patrick Sandusky said.