Morocco's steeplechase world record holder Brahim Boulami has been banned after a positive drugs test.
Boulami's ban is backdated from 28 August, 2002
Urine tests showed Boulami had taken the banned substance EPO in August last year - one day before he set the world's best time in Zurich.
The Court of Arbitration for Sport ruled: "The prohibited substance EPO was present in Brahim Boulami's urine.
"Also, the urine test performed by the laboratory in charge of the analyses was reliable and valid."
There had previously been doubts from the Moroccan Athletics Federation over the testing methods.
Boulami, 31, clocked 7:53.17 on 16 August last year to set a new world mark, but the time may now be scrapped from the record books.