USA Track & Field is under pressure to explain why Jerome Young ran in the 2000 Olympics despite a positive drug test the previous year.
Young took 400m gold in Paris
The International Association of Athletics Federations has pressed for a response from USATF.
And World Anti-Doping Agency chairman Dick Pound backed the IAAF.
"It means that the other teams in the event may have been cheated out of the result that should have happened," said Pound.
He added: "It suggests there are rules for the rich and powerful countries in sport and another set for the small countries."
The IAAF made a new appeal on Thursday in a letter from president Lamine Diack.
"We have explained the need for having this matter concluded in a proper way," said IAAF anti-doping chief Arne Ljungqvist.
"We try to make them understand it is in their interest and our interest. We expect a quick reply and reaction."
Previously, the IAAF and USATF said they were bound by an arbitration ruling protecting anonymity in the case.
"Now that the name of the athlete is known we feel there is no longer any confidentiality to observe," said Ljungqvist.
"I can't see a single reason for not disclosing the information at this stage."