Michael Rasmussen's continued presence on the Tour de France, in the wake of revelations that he has missed several random doping controls in the past two years, is starting to grate with some teams.

Rasmussen reinforced his grip on the race lead with another commanding climbing performance on the first of three days in the Pyrenees on Sunday.

However for some, his march towards victory is an affront.

"I'm angry," said Cofidis team manager Eric Boyer.

Française des Jeux team manager Marc Madiot added: "I've gone past being angry. I just don't want to talk about it anymore. You should go and ask Mr. Rabobank about it."

Rabobank, sponsored by a leading Dutch bank, has been under increasing pressure since Rasmussen admitted he had committed an "administrative error" after missing random doping controls by the UCI on March 24, 2006 and June 28, 2007.

It later emerged he had also been warned twice by Denmark's anti-doping agency after missing two doping tests run by the Danish Cycling Union (DCU) this year.

Under World Anti Doping Agency (WADA) rules, missing three doping controls by any one body amounts to a doping violation.

According to the race's code of ethics, which led to the eviction of 13 riders from the race last year over their alleged link to the Operación Puerto doping affair, suspected riders are prevented from racing.

Tour director Christian Prudhomme told AFP Saturday that had organizers known of Rasmussen’s missed test before the Tour began, “We would have made the Rabobank team face up to their responsbilities."

Rabobank’s Theo De Rooy admitted he had reflected over the case prior to the Tour de France, but said: "We didn't have a positive test for doping on our hands."

But Bouygues Telecom team manager Jean-Rene Bernaudeau said if there's suspicion, riders should be left at home.

"The number one priority is credibility,” he said. “Does being in the yellow jersey, in this way, really interest them now (Rabobank)?"

Prior to the race Prudhomme and UCI president Pat McQuaid had demanded that all participating riders sign a legal waiver and submit a DNA sample to pledge they had not cheated and would not cheat.

Rabobank was among the teams to sign the pledge, but released a statement outlining its opposition: "We acknowledge the problem of doping in cycling and we support the UCI in its fight, but we feel that this measure is contrary to an individual's basic human rights."

The perception in the peloton is that while teams from some countries are ready to adopt a zero-tolerance policy, others are more hesitant.

For Boyer, the only solution is to force a culture of total transparence.

"The UCI failed to demand that the Danish cycling federation, Rabobank and Rasmussen tell everyone - the media and the organizers - of this news prior to the Tour de France," added the Frenchman.

"We don't have the right to hide this kind of information, and certainly not from race organizers. They're the ones who cop the flak as soon as there's suspicion."

For Bernaudeau, Rasmussen's presence casts a dark shadow on the Tour.

"He's been warned several times,” he said. “He's totally on the brink (of a doping violation). But he's still here."

Boyer added: "For the past three years he (Rasmussen) has been a great rider for the three weeks of the Tour. Before and after, we don't know where he is. When you know how the human body of a top cyclist works, it just doesn't make sense."