Giro d'Italia leader Stefano Garzelli has failed a dope test, his Mapei team said today.
Team officials told a news conference the Italian rider, who won the Giro in 2000, had tested positive for probenecid, a diuretic and masking agent.
Garzelli, who strengthened his grip on this year's race by winning Friday's fifth stage, would be allowed to continue in the Giro pending the outcome of a second analysis of his sample on Tuesday in Lausanne.
The Mapei team said they were surprised by the results of the test on Garzelli, which was carried out after Monday's stage to Liege, in Belgium.
"It's crazy that he would take something like this because it's certain to show up in a drugs test," said team press officer Alessandro Tegner.
Team manager Aldo Sassi added: "We don't want to say there's been a plot against us. We are just reporting the facts that we know. We've asked the UCI [International Cycling Union] to test all our riders to see if they're positive for the same product."
Garzelli, wearing the race leader's pink jersey, was close to tears at the news conference.
"My conscience is clear," he said. "I have been preparing for the Giro since last year. I would be an idiot to ruin the race, my career and my life for something like this."