Italian Stefano Casagranda and Slovenian Martin Hvastija have been asked to leave the Tour de France on doping charges, according to Tour director Jean-Marie Leblanc.
"We received a letter from financial investigators from the (Italian) city of Padova advising us that the two riders are under investigation on doping grounds," Leblanc said.
"We advised their team directors and we told them that the riders presence in the Tour was no longer welcome", he added.
Casagranda, 31, who rides for Italian team Saeco, and Alessio rider Hvastija, 34, are both involved in an investigation surrounding an Italian doctor, Enrico Lazzero, which climaxed with police raids on the Giro d'Italia in 2001.
Leblanc had pledged that any rider involved or charged in a doping case would be kicked out of the race.
Briton David Millar, France's Cedric Vasseur and Italian Danilo Di Luca have been barred from the Tour for the same reasons.