Gatlin said he has been informed that he tested positive for testosterone or other prohibited steroids -- the same violation that, only two days ago, threw Floyd Landis' victory in the Tour de France into question.
Gatlin, who positioned himself as a leader in trying to prove track and field is a clean sport, said in a statement released through his publicist that the U.S. Anti-Doping Agency informed him of the test taken after a relay race in Kansas in April.
He said he will cooperate with USADA "and hope that when all the facts are revealed it will be determined that I have done nothing wrong." He could face a lifetime ban from track and field.
"I cannot account for these results, because I have never knowingly used any banned substance or authorized anyone else to administer such a substance to me," Gatlin said. "In the course of my entire professional career, I have been tested more than 100 times. ... All of the tests this season, including the out-of-competition and in-competition tests conducted just before and after the race in Kansas, were negative."
Gatlin, who in May tied Jamaica's Asafa Powell for the world record in the 100 at 9.77 seconds, would lose the record if the result is upheld.
The 2004 Olympic champion is coached by Trevor Graham, whose former pupils include Tim Montgomery and Marion Jones, both of whom have both been prominently mentioned in the BALCO steroids investigation. Several athletes coached by Graham have been suspended or banned for doping.
In an interview on WRAL-TV in North Carolina, Graham said Gatlin doesn't accept supplements from anyone.
"He's got his own nutritional supplements that he goes out and buys," Graham said. "He will not trust anyone to take anything from him, not his parents, his coach, not anyone."
Gatlin's revelation came just days after Landis tested positive for a testosterone imbalance after his stirring comeback victory at the Tour de France. Landis claims his body's natural metabolism caused the result.
The test on the cyclist measured the ratio of testosterone to epitestosterone in his system and found an imbalance. Gatlin's test was different. Called a carbon-isotope ratio test, it is essentially a test that looks only at testosterone, not epitestosterone, and can determine whether the testosterone in a person's system is natural or unnatural. The results of both athletes' tests point to the same type of violation of illegal-substance policy.
In his statement, Gatlin said he tested positive for "testosterone or its precursors." "Precursors" is another term for anabolic steroids.
One of the loudest voices in the quest to clean up his sport, Gatlin he was "particularly sensitive to this issue" because he tested positive in college for a banned substance contained in Adderall, which he took to calm attention deficit disorder. He served a two-year ban in international competition after that infraction, meaning another positive test could result in a lifetime ban.
"That experience made me even more vigilant to make certain that I not come into contact with any banned substance for any reason whatsoever, because any additional anti-doping rule offense could mean a lifetime ban from the sport that I love," Gatlin said.
The New York Times reported that Gatlin has positive results from both of his samples -- unlike Landis, who is still waiting for results from the second half of his. Next, the findings will be reviewed by an independent review board. After that, the case could go to arbitration and Gatlin would have the right to appeal the arbitration.
USADA CEO Terry Madden released a statement Saturday that made no mention of Gatlin.
"USADA will not comment on the facts of any active case since the rules we follow allow for a full and fair process prior to the details of any case being made public," Madden said. "Anyone accused of a doping violation has a right to have his or her case determined on the evidence through the established process and not on any other basis."
USA Track and Field, however, acknowledged Gatlin's statement.
"USA Track & Field is gravely concerned that Justin Gatlin has tested positive for banned substances," USATF executive director Craig Masback said in a statement on the federation's Web site. "Justin has been one of the most visible spokespersons for winning with integrity in the sport of track and field, and throughout his career he has made clear his willingness to take responsibility for his actions."
U.S. Olympic Committee CEO Jim Scherr said Gatlin's revelation, on the heels of Gatlin's positive test, "points out how insidious the problem of doing in sport has become."
"While this news is disappointing, it underscores the commitment we have made to protect the integrity of sport through clean competition," Scherr said. "No one, regardless of their stature, is above the system. We understand that Justin has been working with USADA, and would encourage him to continue doing so."