AIGLE, Switzerland -- Retired sprinter Alessandro Petacchi was among four riders linked to a blood doping ring by the International Cycling Union on Tuesday, and another was sent home from the Giro d'Italia.
Petacchi, who won the points classification at all three Grand Tours, is suspected of using a "prohibited method" in 2012 and 2013.
The UCI said the riders are linked to the doping ring based on evidence from Austrian authorities, who are investigating illicit blood transfusions in multiple Olympic sports.
Petacchi is the most successful cyclist so far linked to the scheme, in which a German doctor allegedly offered doping services around the world.
Two of the four were with the Bahrain-Merida team at the Giro d'Italia before they were suspended. Slovenian rider Kristijan Koren was supporting team leader Vincenzo Nibali, and Borut Bozic, who retired last year, was working as a sports director.
"The team strictly advocates zero-tolerance doping policy and has therefore provisionally suspended both members concerned," Bahrain-Merida said, adding that the cases predated both riders' time with the team. "We would like to stress that both cases relate to the 2012 and/or 2013 seasons. The team always carries out thorough medical checks [including biological passport check] of any new signed rider."
Besides Petacchi, Koren and Bozic, Croatian rider Kristijan Durasek was also provisionally suspended. He is a climbing specialist who was racing this week in the Tour of California for UAE Team Emirates.
In March, Austrian riders Stefan Denifl and Georg Preidler were suspended in the same case. The Swiss cycling federation fired retired rider Danilo Hondo as a coach Sunday after he told German broadcaster ARD he was involved in blood doping. Athletes in cross-country skiing have also come under suspicion.
A German prosecutor working alongside Austrian authorities on the case said in March that as many as 21 athletes from five sports may have been part of the doping ring.