Former Vuelta champion Laurent Jalabert expressed surprise at a French newspaper report which said he used the banned drug erythropoietin in 1998.
"It's a surprise. Obviously I rode in the 1990s," Jalabert told French radio RTL, a station he is a pundit for. "As I said during my hearing at the Senate, I always trusted my three teams.
"I'm taking a blow. I don't know whether there will be other names, if there will be evidence. I cannot challenge this because I don't have evidence," the 1997 time trial world champion added.
"I have not been informed. I wonder how it is that journalists can be aware of that while I am not?"
French sports daily L'Equipe said a 1998 Tour de France sample from Jalabert, which was re-tested in 2004, showed traces of the blood-booster EPO.
"I cannot say for sure say that I have never taken anything banned," Jalabert told a French Senate investigation committee into doping last month.
"I have effectively used products when necessary, in case of lesions or other injuries. At ONCE, in the evening after the stages, the doctor took care of us for our recovery, but we didn't really know what it was.
"A relationship with doctors based on mutual trust was established, so we did not ask any questions. We were treated, I have never said otherwise. Were we doped? I believe we were not."
Jalabert, who quit as France road racing coach earlier this year, withdrew with his ONCE team from the 1998 Tour after protesting all riders were being labelled as cheats in the wake of the Festina doping scandal.
Jalabert, 44, is a leading commentator for French national TV on the Tour de France, which starts on Saturday.
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