Bernhard Kohl, the Austrian cyclist who finished third in last year's Tour de France before testing positive for a previously undetectable form of EPO, has revealed the extent of his doping practices, and claimed the much-vaunted biological passport programme of the International Cycling Union (UCI) is ineffective in ­catching cheats.

In an interview with L'Equipe, Kohl admitted that, as well as taking Cera, a so-called third generation EPO, he performed illegal blood transfusions during last year's Tour, in which he was crowned King of the Mountains. He also claimed a culture of doping is still prevalent in the sport, and that, in his opinion, any rider who finished in the top 10 of last year's race was likely to have doped.

On the biological passports, Kohl said: "The top riders are so professional in their doping that they know very well they have to keep their blood values stable [so as] not to be detected. The UCI sent us the values resulting from the controls: we thus referred to those to mark the next ones. In a way, the passport almost helped us."

Kohl said that his manager, Stefan Matschiner, flew to France three times during last year's Tour, providing half-litre bags of the cyclist's blood, which had been withdrawn prior to the race. "By re-injecting half a litre of blood the blood parameters are not subject to suspect variation." He added: "I did not cheat anyone in the peloton, be sure of that – there is like a social organisation [of doping] within the ­peloton, these things are accepted."

The UCI, which launched the passport last year, claiming that it represented a new frontier in the fight against doping, has come under fire for a perceived lack of progress. So far, despite huge investment, it has failed to produce a single positive case. But Michael Ashenden, one of the UCI's panel of experts charged with overseeing the passports, countered Kohl's claims. Ashenden suggested the first positive cases would be revealed "within the next few weeks".

There is speculation that they could even come as early as today, with the UCI president, Pat McQuaid, due to hold a press conference in Paris with the organisers of the Tour and the French anti-doping agency. Asked whether the press conference could be linked to the first biological passport cases, Ashenden said: "I can't comment on that."

Attacking Kohl's claims that riders know how to get around the biological passports, Ashenden said: "I don't accept, without knowing what his [passport] profile looked like, that it wasn't suspicious. It may have been, it may not have been.

"There is an international focus on the UCI right now because they're seen as the first [sporting] federation to [establish a biological] passport. With that comes a lot of pressure to get it right. The delay we're seeing [in terms of the first positive cases] is to make sure every element is cross checked and verified before the case is brought, to make sure there's nothing that causes a case to be thrown out on a technicality. But I think you'll find in the next weeks there will be announcements."

Among Kohl's claims were that "micro-dosing" of EPO was undetectable, even by the passports. The Austrian said tiny doses of EPO added to his own blood – before it was re-transfused – meant that illegal blood transfusions could not be detected. "I can understand the rationale behind that," Ashenden said. "[But] it would then make the athlete prone to being caught for EPO, which we can detect. There's a trade-off: you can transfuse blood and risk being caught by the passport, or use EPO and risk being caught for that.

"Of course it's possible that riders could find a way around the passport. It would be naive to sit back and think they're not going to try to find a way around it. They've tried to do that every time we've brought in a new test in the past and I expect they'll do that every time we bring in a new test in future. But the passport is the best strategy we have; it's not perfect, but it's the best we've got."