Giro d'Italia: Bradley Wiggins just clings on as infection takes its toll

Wiggins: 'I've had a pretty rough 24 hours' (EPA)

A chest infection was the latest setback to hit Britain's pre-race favourite Sir Bradley Wiggins on the Giro d'Italia.

The Tour de France champion finished the 11th stage in the main pack behind the winner Ramunas Navardauskas to stay fourth overall, 2min 5sec behind the leader Vincenzo Nibali.

"I'm not feeling very good at the moment, I've had a pretty rough 24 hours," Wiggins said. "I've got a chest infection and a bog-standard head cold. Fortunately in these days, these kinds of stages, there's just a bit of fighting and you can get through them and hide a little bit. But I just want to try and fight through it and hope that in a few days' time I'll be all right."

Nibali maintained his lead over Wiggins on a day when cycling was again tainted by drugs allegations as a French rider tested positive for a banned substance. The International Cycling Union said before stage 11 that Sylvain Georges had failed a test for the stimulant Heptaminol in a sample taken last Friday.

Georges, of the AG2R team, pulled out of the Giro this morning, but the team director, Vincent Lavenu, said the positive test occurred because Georges had mistakenly taken a performance-enhancing drug. "He told me he had used a product because he had heavy legs, thinking it was harmless," Lavenu said. "There was no intention to dope. But it's a silly mistake that hurts him and the whole team. The consequences are disastrous compared to the original action."

The 29-year-old, who won a stage of the Tour of California last year, has not been given a provisional ban because under the governing body's anti-doping rules Heptaminol is a specified substance and can be used in certain circumstances.

Navardauskas broke free to win the stage and give cheer to his Garmin-Sharp team. The Lithuanian took advantage when a large breakaway group splintered towards the end of the 182km (113-mile) run from Tarvisio to Vajont. Garmin-Sharp's defending champion Ryder Hesjedal had seen his challenge effectively ended in the past few days.