Mellouli allowed Beijing entry

The ban, which dates back to the time of the doping offence, leaves Mellouli eligible to compete at next year8217;s Beijing Olympics.

Mellouli won gold in the 800-meter freestyle and silver in the 400 freestyle in March at the world championships in Melbourne. He was the first Tunisian to win a gold medal at a world championships.

CAS ruled that those medals and all of Mellouli8217;s results back to November 30, 2006, are annulled.

CAS decided against the 2-year ban because Mellouli, who was studying at the University of Southern California at the time of the positive test, admitted he took the substance.

8220;The swimmer admitted that he had taken an Adderall pill two days earlier to prevent him from falling asleep so that he could finish writing a report which counted towards his final university diploma,8221; CAS said.