The International Olympic Committee (IOC) has confirmed LaShawn Merritt will not be able to defend his 400m title in London.
The American has been handed a 21 month suspension backdated to October 28 last year after testing positive for a banned substance.
And while the drugs were contained in a male enhancement product used by the athlete rather than taken to boost performance, the IOC rules say he must sit out the next Olympic Games.
“The (IOC) rule states very clearly that any athlete sanctioned for six months or more will be banned from participation in the next edition of the Games,” IOC director of communications Mark Adams said.
“This rule is still valid and applies to all athletes
“Each case is of course different and subject to potential legal procedures but the IOC’s rules are clear, coming into force just before Beijing in July 2008.”
The American Arbitration Association, who handed down the ban, claims the IOC ruling goes against the World Anti-Doping Agency code, and therefore cannot enforce an Olympics suspension on Merritt.
