World 100m record holder Tim Montgomery has accused banned sprinter Kelli White of giving the United States Anti-Doping Agency information against him.
Montgomery set a record 9.78 seconds for the 100m in 2002
Montgomery is one of four American athletes who USADA wrote to alleging possible doping violations.
But Montgomery has always denied taking performance enhancing drugs and said: "They don't have anything on paper.
"It's all someone saying something... Kelli White. She don't live with me, so I don't know how she would know."
World 100m and 200m champion White was banned for two years in May after testing positive for modafinil at the World Championships in Paris last year.
But Montgomery's lawyer Christina Arguedas insisted he had "done nothing wrong".
"USADA alleges that it 'anticipates' testimony from
unidentified witnesses regarding Tim's alleged admission of the use of banned substances," Arguedas said
in a statement.
"Tim has done nothing wrong, and we intend to vigorously fight any attempt by USADA or any other sports organisation to deny him the opportunity to fulfill his dreams and participate in the 2004 Olympics."
"How can you have a testimony about someone when you're not swearing under oath?" Montgomery added. "It's crazy."
Arguedas added that nearly all the allegations in USADA's letter to Montgomery came from the files of Victor Conte, the man who set up the California nutritional supplement company BALCO, which is the subject of a federal grand jury investigation.
But Montgomery said: "I only knew the guy for six months. I only knew him from working with CJ Hunter in Sydney. The truth will prevail."