Britain's Jonathan Tiernan-Locke is to face disciplinary proceedings over an alleged "anti-doping rule violation".
The charge stems from irregularities in the 28-year-old's biological passport, which were initially uncovered in September.
An International Cycling Union (UCI) statement said: "The analysis of the biological passport of Mr Jonathan Tiernan-Locke by the Experts Panel has demonstrated an anti-doping rule violation [use of prohibited substances and/or methods].
"Consequently, and in compliance with the UCI Anti-Doping Rules, the UCI has requested his National Federation to initiate disciplinary proceedings."
'Denies the charges'
Tiernan-Locke, who was asked by the UCI in September to explain the anomalies, denies any wrongdoing and has vowed to fight the charges.
A statement from his management company, Trinity Sports Management, said: "Jonathan Tiernan-Locke was notified that the UCI wish to instruct British Cycling to instigate proceedings against him regarding an abnormality in his biological passport.
"Mr Tiernan-Locke vehemently denies the charges brought against him and has informed the UCI that he fully intends to contest them. Mr Tiernan Locke will not ride for Team Sky, attend training camps or undertake any team duties until a decision is made in these proceedings.
"Mr Tiernan-Locke is looking forward to a speedy and just resolution of these unfortunate charges. Until a decision has been reached, Mr Tiernan-Locke will make no further comment on the matter."
The biological passport monitors cyclists' blood and urine to highlight discrepancies that may indicate the use of banned substances.
'Not ride for Team Sky'
Tiernan-Locke won the Tour of Britain in September 2012 while representing the Endura Racing team. It was his third stage-race victory of the season after triumphs at the Tour Mediterraneen and Tour du Haut Var, both in France.
Tiernan-Locke agreed to join Team Sky in October 2012 and the anomalies are believed to have occurred in September 2012.
A Team Sky statement released on Tuesday said: "Jonathan Tiernan-Locke will not ride for Team Sky or take part in any team activities - including training camps and all team duties - until a decision is made in this disciplinary hearing process.
"We understand that the violation was highlighted by an anomaly in his Biological Passport, in a reading taken before he signed for this team.
"There are no doubts about his approach or performance in Team Sky. This is a team that trains, races and wins clean. At this stage, we will add no further detail until this initial disciplinary process is concluded."