Briton Jonathan Tiernan-Locke has withdrawn from racing after being questioned by the International Cycling Union (UCI) over a discrepancy in the 2012 Tour of Britain winner's blood data, his Team Sky said on Sunday.
"Team Sky has been informed by Jonathan Tiernan-Locke that the UCI has notified him of a potential discrepancy in his biological passport data," the British outfit said in a statement.
"He has withdrawn from racing whilst his response to the UCI is prepared then considered by the UCI.
"We have no doubts over his performance, behaviour or tests at Team Sky and understand any anomaly is in readings taken before he joined the team."
Team Sky had said on Thursday that Tiernan-Locke, who joined the outfit this year, had pulled out of Sunday's world championships elite race.
"Team Sky has tried to respect what should be a confidential process, allowing the rider to explain in private, without prejudice, and the anti-doping authorities to do their valuable job," Sky's statement further read.
"At this stage in the ongoing process, we will not add any further detail."
The 28-year-old, who finished 19th in last year's world championships road race, won the Tour of Britain, the Tour Mediterranéen and the Tour du Haut Var in 2012 but has yet to taste success since joining Sky.