US Sprinter Tim Montgomery has announced his retirement from athletics following his two-year ban for steroid abuse.

The 30-year-old American was stripped of his 100 metres world record, his gold and silver medals from the 2001 World Championships and had all his results since 31 March 2001 expunged from the record books.

He also confirmed that he has split up with partner Marion Jones, the triple Olympic champion at the 2000 Sydney Games.

The charges were brought by the US Anti-Doping Agency based on evidence gathered in the Balco laboratory case. "I have retired," he said to the BBC. "The process was totally not fair. From where I come from, you need a positive test."

But, the World Anti-Doping Agency president Dick Pound told reporters he believes the bans will serve as a warning that officials do not need positive tests to punish athletes. "It is a good warning. It means if you are going to do this drug stuff you are at risk. This will be helpful as a deterrent," he said.