The International Cycling Union (UCI) on Sunday insisted that Tour de France champion Chris Froome's use of a steroid-based drug in competition had not broken anti-doping rules.
According to a French newspaper, Froome was suffering from a cold and was granted permission to use penisolone on his way to winning April's Tour de Romandie in Switzerland.
Froome was permitted to take up to 40mg of the drug a day in tablet form after Team Sky doctor Alan Farrell was given the go ahead by UCI medical director Mario Zorzoli.
However the UCI insisted that no rules had been broken and that Froome, who lost his Criterium du Dauphine title on Sunday, had not been given any special treatment.
"Christopher Froome's TUE (therapeutic use exemption) for oral use of glucocorticosteroids was granted on April 29, 2014 based on duly documented medical history and in compliance with the applicable UCI Regulations and the relevant WADA guidelines," read a UCI statement.
"The TUE was granted for a limited period, following the usual procedure.
"The process was fully transparent as it is UCI's policy to systematically record all TUEs on ADAMS. WADA was therefore informed throughout the process.
"The UCI wishes to emphasise that under the applicable rules, which are consistent with the WADA Code and the WADA TUE Standard and Guidelines, any rider with the same symptoms as Christopher Froome would have received a similar TUE."
Team Sky rejected the allegations and dismissed accusations of collusion because UCI president Brian Cookson's son is on the Sky staff.
"That's ridiculous," snapped team boss Dave Brailsford.
Cookson was president of British Cycling before his election as UCI supremo last year and Brailsford said: "I've worked with Brian for 16 years at British Cycling and no-one has ever said anything. His son works with us, but I don't think that raises any questions."
He added: "Dr Zorzoli, the UCI doctor, told us what we could and couldn't do, we've always stayed within the rules, so we've got nothing to hide."
Froome, meanwhile, was forced to defend his use of an inhaler on his way to winning the second stage of the Criterium du Dauphine last week.
"I have had an inhaler since childhood, I have exercise induced asthma," said the Tour de France winner. "It is ok. I didn't need a TUE."