Dwain Chambers' former coach has admitted distributing performance-enhancing drugs to athletes as part of the Balco steroid scandal.
Remi Korchemny, 73, told a US Federal Court he wrongly dispensed the prescription drug modafinil to an athlete on 4 July 2002.
But he added: "Steroids and stimulants, according to the names on the boxes, I passed them on to athletes."
Korchemny said the substances had come from Balco founder Victor Conte.
Under a plea agreement, the Soviet-born coach will not serve any prison time for the misdemeanour.
Conte and his deputy Greg Anderson have already reached plea deals with prosecutors which look set to result in short prison sentences.
A number of Korchemny's athletes have received bans from athletics, including Chambers and US sprinter Kelli White.
US District Court Judge Susan Illston is due to issue her sentences in the Balco cases on 18 October.