Vitali Klitschko, who defends his World Boxing Council heavyweight title
against Britain's Danny Williams in Las Vegas on Dec 11, has admitted to having used steroids earlier in his career.
He tested positive for a banned substance in 1996 when still an amateur and was instantly thrown off the Ukrainian boxing team for the Atlanta Olympics.
Klitschko had planned to box at super-heavyweight while his younger brother, Wladimir, was entered to compete at the 201lb heavyweight limit.
Wladimir, who was struggling to make his weight, took over the super-heavyweight slot and went on to win the gold medal.
"Their dream was to go to the Olympics and win gold medals together," said Vitali Klitschko's spokesman, Bernd Boente