The laboratory conducting the follow-up test on Spanish cyclist Roberto Heras's urine sample found traces of EPO that confirmed an earlier test.
The finding means that Heras could be stripped of this year's record-setting fourth Vuelta a Espana title and be banned from professional cycling for two years.
He joins a group that includes Italian Marco Pantani, Frenchman Richard Virenque and American Tyler Hamilton who rightly or wrongly have had their careers interrupted, and ruined, by doping scandals.
Heras's lawyer announced the findings this way outside the lab: “Surprisingly the test was positive,” reported Reuters news service.
Heras had vehemently denied any wrongdoing and has maintained his innocence. His attorneys have promised to challenge the findings in court, if they were returned to be positive.
At a press conference, Heras said: “I never doped myself, I didn't do it during the Vuelta nor at any other time. I've always won cleanly. I can't allow all my sacrifices to be trampled due to an error. I have to take the result on board, but I question it.”
The sample was taken in the next to last stage of this year's Vuelta. The Liberty Seguros team was notified in late October and suspended Heras, pending the outcome of the “B” sample test which was conducted this week.
Russian cyclist Denis Menchov, who finished second in the Vuelta, will be awarded this year's title.