Jonathan Tiernan-Locke has been given a backdated two-year ban and had his contract with Team Sky terminated over discrepancies in his biological passport.
The International Cycling Union (UCI) were made aware of the anomalies last September and subsequently asked UK Anti-Doping to initiate disciplinary proceedings against the 29-year-old Englishman in December.
The adverse results were recorded in September 2012, the same month Tiernan-Locke won that year’s Tour of Britain and a month before he agreed to join Team Sky.
His hearing was delayed until this summer, and although he has always denied any wrongdoing, a disciplinary panel did not accept his explanation for the abnormalities and he has consequently been banned until January 1, 2016.
Tiernan-Locke’s 2012 Tour of Britain win has also been scratched from his record.
A UCI statement said: "A two-year ban was imposed on the rider as a result of his anti-doping rule violation based on his Athlete Biological Passport.
"He is declared ineligible until December 31, 2015 and disqualified from the 2012 Tour of Britain and the 2012 UCI Road World Championships, competitions during which abnormalities were clearly identified."
Team Sky principal Sir Dave Brailsford said: “Jonathan’s contract has been terminated today. Whilst there have been no doubts about his time with us, his doping violation - from readings taken before he joined this team - means there’s no place for him in Team Sky.
“We have a well-known stance on anti-doping and our action is the inevitable outcome of a violation. This is a team that trains, races and wins clean.”
Tiernan-Locke also won the Tour Mediterraneen and Tour du Haut Var in 2012 but will keep both those titles as they took place before his anomalous biological passport results were recorded.
He has not raced since last September and has not taken part in any Team Sky events since the violation came to light.
A Team Sky statement said: "Team Sky was first aware of an issue in September 2013. Senior management immediately looked into the case and also reviewed recruitment processes. These will continue to be assessed, on an ongoing basis, with the support of the team’s compliance officer, appointed in the autumn.
"Jonathan Tiernan-Locke has not raced for the team since September 2013 and has not taken part in any team activities - including races, training camps and public appearances - since he was formally notified of a UCI anti-doping violation, then immediately announced his appeal, on 16 December 2013."