Disgraced sprinter Tim Montgomery has announced his retirement from the sport after receiving a two-year ban for steroid abuse.
The 30-year-old was banned by the Court of Arbitration for Sport on Tuesday despite not testing positive for drugs.
The charges were brought by the US Anti-Doping Agency based on evidence gathered in the Balco laboratory case.
"I have retired," he said. "The process was totally not fair. From where I come from, you need a positive test."
Montgomery, whose ban expires in the summer of 2007, has denied ever "knowingly" taking a banned substance.
As well as the ban, Montgomery was stripped of his 100m world record, the gold and silver medals he won at the 2001 World Championships and has had all his results since 31 March 2001 removed from the record books.
The International Association of Athletics Federations ordered him to return all winnings earned since 31 March 2001.
Montgomery also confirmed that he has split up with partner Marion Jones, the triple Olympic champion at the 2000 Sydney Games.