Former cycling world champion Alessandro Ballan has been suspended by BMC Racing because of his implication in a doping investigation in Italy, the American team said on Friday.

Ballan, 30, and Mauro Santambrogio, who has also been suspended, are both former members of the Lampre team which has been targeted by the investigation.

"It has come to our attention that two of our riders, Alessandro Ballan and Mauro Santambrogio, are the subject of an investigation by Italian authorities stemming from incidents that took place more than two years ago," BMC team president Jim Ochowicz said in a statement.

"The BMC Racing Team and its members were not aware of this investigation until a few days ago and we hope to obtain more information about the proceedings.

"However, we have already made the decision to withhold the two from competition, in accordance with the BMC Racing Team's own policy and the UCI's Code of Conduct."

Italian media reported that there were 35 riders, doctors and team managers being investigated with Ballan, who won the world title in 2008, saying on Wednesday he was being probed.

"This should not be seen as pre-determination of guilt in connection with the Italian investigation," Ochowicz said of the suspension. "Both will have to personally address the accusations."

Italy's Lampre have denied any wrongdoing but said members of their team were being investigated and they are awaiting further clarification before taking any action.

"We have had no notification from the prosecutors. Our riders will keep racing for the moment," a spokesman said.

"The prosecutors have said in the press that many of the people under investigation will probably not be charged. We hope to have notification soon and then we'll decide. For now we have so little information."