The Court of Arbitration for Sport has denied the appeal by Greek sprinters Konstantinos Kenteris and Ekaterina Thanou to be allowed to return to competition.
The court refused to lift the sprinters' provisional ban until after it rules whether Kenteris and Thanou deserve suspensions for missing three doping tests before the 2004 Olympics in Athens.
The Lausanne-based court said Monday it will take up the case again on June 26, and plans to render its ruling within two to three days. But the ban will stand until a decision is reached.
Kenteris was the 200-meter Sydney Olympics champion in 2000, while Thanou won the women's 100-meter silver medal at the same Games. They were provisionally suspended by the athletics world governing body, IAAF last year after the Greek Athletics Federation refused to punish them.
Some information for this report was provided by AFP.