Ricco was the runner-up in the Giro d'Italia. He won the sixth and ninth stages and was ninth overall before the start of yesterday's stage, two minutes, 29 seconds behind Evans.
Ricco had come under suspicion about what he says is his naturally high hematocrit level - the volume of red blood cells. High hematocrit levels can suggest use of EPO, but do not confirm it.
Following his victory in the ninth stage, Ricco said he has had high hematocrit levels "ever since I was little," adding, "I hope soon that everybody will stop speaking about that."
Ricco's popularity in Italy rocketed with his two Tour stage wins, even gaining front-page coverage in the football-focused Gazzetta dello Sport.
The rider has said his idol was Marco Pantani - the last Italian to win the Tour, in 1998. Pantani faced doping allegations throughout his career. He died of a cocaine overdose on Valentine's Day in 2004.
The news on Ricco came even as judicial officials continued to question Spanish rider Moises Duenas Nevado, who was expelled from the race on Wednesday after Bordry announced he had tested positive for EPO - like Ricco, after the fourth stage.
Duenas Nevado was detained by police on Wednesday in the southwestern town of Tarbes, at a hotel where his Barloworld team was staying. Police also searched his hotel room.
Gerard Aldige, the state prosecutor in Tarbes, said that police found "numerous small medical materials like syringes, needles, and medical drip bags which theoretically a cyclist should not have in his room."
Liquigas team rider Manuel Beltran - a former teammate of seven-time Tour winner Lance Armstrong - was kicked out of the Tour and sent home to Spain on July 11 after he also tested positive for EPO.
(Agencies via Shanghai Daily July 18, 2008)