The American runner received a 21-month suspension from US arbitrators on Monday for using a banned substance found in an over-the-counter male enhancement product.
The ban expires in July 2011, leaving Merritt eligible to compete in the world championships in Daegu, South Korea, in August next year.
But the International Olympic Committee reiterated that its rules will keep Merritt out of the London Olympics.
Under a rule adopted in Osaka, Japan, in 2008, any athlete suspended for more than six months is automatically banned from the next Olympics.
“Each case is of course different and subject to potential legal procedures,” the IOC said in a statement.
“But the IOC's rules are clear, coming into force just before Beijing in July 2008. The Osaka rule states very clearly that any athlete sanctioned for more than six months will be banned from participation in the next edition of the games.
“This rule is still valid and applies to all athletes.
Merritt also won gold in the 4x400 relay in Beijing and in the 400 at the 2009 world championships in Berlin.
The American tested positive for testosterone prohormones three times between October 2009 and January 2010. He cooperated with doping authorities, and arbitrators took three months off the normal two-year ban for first-time offenders.
In finding Merritt's use of a product called Extenze, the arbitration panel wrote that Merritt's conduct “was exemplary and demonstrated tremendous character in making what had to be a painful and humiliating confession.” In a statement released through his attorney, Merritt said he appreciated the arbitrators' decision to cut the suspension by three months.
“While I acknowledge that I made a mistake, I appreciate that the Arbitration Panel listened to all of the evidence, and agreed that I have never taken any substance to gain an advantage on the track,” Merritt said.
