A key adversary of Lance Armstrong has questioned the ethics and morals of Team Sky and Chris Froome on the eve of the start of the Briton's Tour de France defence in Yorkshire.
Anti-doping advocate Christophe Bassons, nicknamed 'Mr Clean' after infamously refusing to be cowed by bullying drug cheat Armstrong, believes it was wrong for Froome to race at April's Tour de Romandie requiring a therapeutic user exemption certificate for asthma medication.
None of the rules in place by the UCI, cycling's world governing body, and the World Anti-doping Agency, were infringed but Bassons thinks Team Sky and Froome compromised their principles.
"Doping is about eliminating all obstacles to win a race," Bassons told Press Association Sport.
"I ask myself a lot of questions about Team Sky. I have the impression that they talk a lot and say a lot of things because they don't want to talk about other things.
"The fact is Froome has shown his mentality by taking this product. He had a problem, he was ill and he took this product. He eliminated the obstacle to him winning.
"It's not that different from taking EPO (the blood-boosting agent which was the drug of choice in the Armstrong era) because you're tired and your haematocrit is low.
"Just because it's legal, it comes down to the same mentality.
"Armstrong said years ago 'I've been tested 500 times and never tested positive'. That's the same mentality guys have got today. They just don't want to test positive.
"It's not about where the authorities draw the line, because people thinking about that are also only thinking the priority is not to test positive.
"My dad was a bricklayer. If he was ill he wouldn't take a drug so he could carry on, he'd go home and rest.
"There seems to be this obligation with Sky to perform at any cost. That worries me."
Bassons drew unfavourable comparisons between Team Sky and Armstrong's United States Postal Service team, whose sophisticated doping programme was exposed by the United States Anti-doping Agency two years ago.
"What's also true is Sky have definitely gone against a lot of received knowledge in the sport," Bassons added.
"There were a lot of things we thought weren't possible and they've shown that they are possible.
"They have a collective force like US Postal had, they communicate with people like US Postal did and they seem to produce riders who don't have any muscles and are very powerful.
"Twenty years ago, almost, it was Festina, 10 years later it was Armstrong. I don't want to say that in the next few years Froome is going to be the next big scandal, but what they ought to do if they've got nothing to hide is communicate differently and stop communicating in that way, like US Postal used to do."
Team Sky insisted it abided by the rules in place.
Team Sky principal Sir Dave Brailsford said: "We set out to try to win this race with a British rider and ride clean and we've achieved that.
"We're a clean team, we play by the rules. We are happy that WADA is happy with us and we are happy that the UCI is happy with us."
Bassons was in Leeds to promote the updated and translated version of his autobiography, 'A Clean Break'.
He believes doping is now limited in cycling due to the implementation of measures to combat it, but more could be done to educate riders and change mentalities.
"For 15 years now the message of what I've been saying has not been heeded," Bassons added.
"Mentalities haven't changed enough. Too much emphasis in anti-doping is put on how dangerous it is for your health and that has not worked.
"What really it needs to do is work on prevention and make young people confident enough in their own skin that they don't need to dope."
:: A Clean Break - My Story by Christophe Bassons with Benoit Hopquin is published by Bloomsbury £16.99.