HONOLULU -- The Honolulu Marathon on Tuesday announced it disqualified the 2007 men's winner after he tested positive for a banned substance.

The U.S. Anti-Doping Agency tested Ethiopian Ambesse Tolossa and found an opiate in two samples, Honolulu Marathon officials said.

"Did it have an impact on the finish results? Maybe, maybe not. We don't know. But, the fact is he had a banned substance in his body," Co-Race Director Ken MacDowell said.

Ambesse Tolossa did not have a performance-enhancing drug like steroids, but opiates like morphine found in his body are prohibited.

"We're not sure why that would be in his body. We don't know the levels that are in his body, 'cause we're not privy to that information, because of privacy concerns, we can't see that," MacDowell said.

The marathon withholds the prize money until after the testing, officials said.

"We don't want somebody that tests positive to walk away with a fistful of dollars, you know, and we're out the money, and in this case, if he had been paid the money, he's paid the money and we're not going to get it back," MacDowell said.

The disqualification means that the runner up, Kenya's Jimmy Muindi, wins his sixth title. He will receive the $40,000 prize.

Honolulu Marathon President Jim Barahal brought back testing after the 2006 women's winner, Lyubov Denisova, of Russia, tested positive three months later.

Ethiopia's sports federation has suspended Tolossa. He will also be banned from international competition until April 4, 2010.