World 100 metres champion Torri Edwards will learn on Tuesday if she will be able to compete in the Athens Olympics after a positive test for the stimulant nikethamide.
A Court of Arbitration for Sport (CAS) panel convened on Monday evening to consider an appeal by the 27-year-old American against a two-year ban.
Officials said the independent body would consider the panel's findings and announce a decision on Tuesday.
The athletics programme begins at the Olympic stadium on Friday after the men's and women's shot put finals at ancient Olympia two days earlier.
Edwards and her manager Emanuel Hudson entered the temporary CAS headquarters at an Athens hotel without speaking to waiting reporters.
She was confirmed as world champion when her fellow-American Kelli White accepted a two-year ban after admitting taking several performance-enhancing drugs.
However, Edwards in turn was banned for two years by the US Anti-Doping Agency (USADA) last Wednesday after a positive test for nikethamide at a meeting in Martinique last April.