British cyclist Simon Yates failed a drug test but his team are saying it was caused by an "administrative error" over an asthma inhaler.
Simon Yates tested positive for Terbutaline on 12 March while racing from Paris to Nice.
According to his team, the substance was being used to treat "documented asthma problems".
Mr Yates, from Bury in Greater Manchester, has been described as one of Britain's brightest prospects and is a strong contender to make the TeamGB road race team for the Rio 2016 Olympics.
The 23-year-old joined the Australian team in 2014.
The substance was given to Simon Yates in the form an asthma inhaler and accordingly, this was noted by the team doctor on the Doping Control Form, signed at the time of the test.
A British Cycling spokesman told the Daily Mail: "British Cycling can confirm that it has been notified by the UCI of a potential anti-doping rule violation against a British rider based on an analysis of a sample provided in competition.
"As with any other doping violation charge at this level, those proceedings will be managed independently of British Cycling by the UCI."
What is Terbutaline?
Terbutaline is a drug commonly used to relieve asthma symptoms but is also prescribed for bronchitis and emphysema. Its use is permitted in cycling, as long as the user is given a therapeutic user exemption certificate (TUE) in advance.
In Yates’ case, it is alleged the team doctor declared it on the doping form, without having obtained a TUE.
Why is it banned?
Terbutaline is classified as an adrenergic agonist that causes muscles to relax, giving the user an easier airway to breathe. The drug can be administered as a tablet or a solution for injection, however for the safety of athletes its use is only permitted if inhaled with a TUE.
Are there any previous cases of cyclists using Terbutaline?
In 2015, Team Sparebanken Sor rider Vegard Robinson Bugge tested positive for Terbutaline. He was provisionally suspended from the team and handed a four month ban.