Bas Czerwinski / AP Riccardo Ricco of Italy and the Saunier Duval-Scott cycling team, right, is led away by French gendarmes prior to the start of the 12th stage of the Tour de France on Thursday. Ricco is the third cyclist who tested positive for the use of EPO in this Tour de France.

NARBONNE, France — With the competition reduced to an afterthought, the Tour de France was rocked by another drug bust Thursday that left cycling's showpiece event all but synonymous with doping.

This was the third time in this race that a rider has been caught, and it netted the biggest name yet: Italy's Riccardo Ricco, a winner of two stages.

"You can't believe that a wave of a magic wand can change the world of cycling," Patrice Clerc, head of Tour organizer ASO, told a news conference. "It's going to take time."

Ricco was expelled from the race and detained by police to the boos of fans. His Saunier Duval team pulled out of the Tour and suspended all its activities. This is the third straight year the Tour has been undercut by doping.

The day's 12th stage was won by Mark Cavendish of Britain while Cadel Evans of Australia retained the yellow jersey. But, as is often the case in cycling, drugs overshadowed all.

"May the cheaters get caught. May they go away," Tour president Christian Prudhomme said. "I said to the riders before the race, behind closed doors, that you have the key. ... Some didn't get the message."

Evans welcomed the drugs busts, and "that the sport is being cleaned up in serious, fair and transparent way. Our sport is being crucified for doing the right thing."

As the stage got under way, Evans rode alongside the car of the Tour director, and said: " Rest assured, we're on the road toward a clean sport,' " Prudhomme told The Associated Press.

All three riders were ousted for the performance enhancer EPO — cycling's drug of choice. Ricco tested positive after the fourth stage, a time trial in Cholet.

"It's just amazing. It's irresponsible," said David Millar, a British rider with the Garmin-Chipotle team. "This guy does not have any love or care for the sport."

Millar, who rode with Saunier Duval last year, has become a leading critic of drug use after serving a two-year doping ban.

The Saunier Duval bus was later detained by gendarmes, and its contents were inspected, the state prosecutor for the Foix region, Antoine Leroy, said by phone.

Pierre Bordry, head of the French anti-doping agency, announced the positive result just before the stage. Some of Ricco's teammates had already taken the starting line before returning to the team bus.

"It's a team decision not to start the race," Saunier Duval sporting director Matxin Fernandez said. "He's our leader. We can't act as if nothing happened."

Ricco, the Giro d'Italia runner-up, won the sixth and ninth stages of this Tour and was ninth overall entering Thursday. He was 2 minutes, 29 seconds behind Evans.

"We are learning that things that look too good to be true are too good to be true," Millar said.

The case was at least the ninth doping-related scandal at the last two Tours.

Ricco's popularity in Italy rocketed with his two stage wins, drawing front-page coverage in the soccer-focused Gazzetta dello Sport.

The rider has said his idol was Marco Pantani, who in 1998 became the last Italian to win the Tour. Pantani faced doping allegations throughout his career and died of a cocaine overdose in 2004.

Ricco's ouster came as judicial officials questioned Spanish rider Moises Duenas Nevado, who was expelled from the race Wednesday. Duenas Nevado was detained by police in Tarbes, where his Barloworld team was staying. Police searched his hotel room.

Gerard Aldige, the state prosecutor in Tarbes, told the AP that police found "numerous small medical materials like syringes, needles, and medical drip bags, which theoretically a cyclist should not have in his room."

Aldige said Duenas, who was released Thursday, faces preliminary criminal charges for "holding and using poisonous substances or plants" and "prohibited importing of merchandise."

Also found were capsules and gels, but their composition must be tested, Aldige said. He said one medicine not authorized for sale in France was uncovered, though he did not elaborate.

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.

"The Tour needs to continue and get to the finish in Paris," International Cycling Union president Pat McQuaid said by phone. "It's another blow to the sport but I have to see it in light of the fact that they're getting caught and going to be thrown out."

In addition to Beltran, Floyd Landis, Roberto Heras and Tyler Hamilton — all former Postal riders during Armstrong's seven Tour wins — failed doping tests after quitting the Texan's team.

Saunier-Duval is the first team to drop out of this year's race. Last year, two teams withdrew and race leader Michael Rasmussen was kicked out days before the end for lying about his whereabouts to avoid pre-Tour testing.

This year, organizers pledged a tougher approach. Eight chaperones shadow riders after each stage, even climbing onto team buses, to ensure that cyclists go to doping checks.

On Thursday, Cavendish led a group sprint to the finish after the 105-mile ride from Lavelanet to Narbonne. Evans, trailing in the main pack, leads Frank Schleck of Luxembourg by one second and Christian Vande Velde of the United States by 38. It was Cavendish's third stage victory this year.

"Every time it's special," he said.

Cavendish, a Team Columbia rider, had never won a stage before this year. He was followed by Sebastien Chavanel of France and Gert Steegmans of Belgium.

The race moves along the Mediterranean today for the 13th stage, a 113-mile ride from Narbonne to Nimes.