Olympic 100 metres champion Justin Gatlin has failed to have a four-year doping ban overturned by the Court of Arbitration for Sport (CAS).
The CAS decision means the 26-year-old will not be able to compete in the US Olympic trials in June and will not defend his crown in Beijing.
Gatlin was given a four-year ban by an American Arbitration Association panel in January after he tested positive for the male hormone testosterone in 2006.
The longer ban was imposed because it was deemed his second doping offence after he failed a doping test in 2001 because of medication for Attention Deficit Disorder.
Gatlin's attorney Maurice Suh maintained that his client's original positive in 2001 should not have been used to increase the punishment for the 2006 case.
Had the U.S. panel not considered the 2001 test, Gatlin would probably have received a two-year ban as a first-time offender and could have been eligible for the U.S. trials.
In making their decision CAS also altered the commencement date of Gatlin's period of ineligibility from May 25, 2006 to July 25, 2006 -- the date when he voluntarily accepted a provisional suspension.
All his results for the three-month period from April 22, 2006, when his sample was taken, will be voided.
CAS rejected a call from the International Association of Athletics Federations to impose a life ban on Gatlin, but his career looks to be in tatters as he will not be able to compete again for two more years.
"While I am pleased that the arbitrators rejected a life ban, I will continue to fight for my right to participate in the great sport of track and field in a time frame shorter than four years," Gatlin said in a statement.
"I have never been involved in any intentional doping scheme, and I think that CAS would not have rejected IAAF's position unless it also believed that I had not participated in any intentional doping."