Olympic medallist and ex-world champion Rob Hayles has been "withdrawn from competitions" for two weeks following an anomaly in his blood test.
Hayles' test showed levels of haematocrit exceeding international governing body rules.
Cycling's international governing body, the UCI, announced that during a routine health check the Britain Cycling Team member had recorded an anomaly in his results.
That anomaly was confirmed as haematocrit levels of 50.3%, slightly higher than the permitted 50%.
While the results require further investigation, Hayles is not under suspicion as the test does not provide proof of blood doping.
Hayles, who won two silver medals at the 2004 Olympics, was due to compete in the individual pursuit event at this week's World Track Championships in Manchester, but will now undergo further checks as British Cycling work with the UCI to determine the reason for the anomaly.
Dave Brailsford, British Cycling performance director, said: "We are totally supportive of the screening system.
"Considering the thousands of tests performed on our large squad by now, it is not unusual to get one or two such anomalies. Indeed we have had riders in the past who have recorded such anomalies during screening and which have been proved to be entirely normal.
"This morning's screening has shown an anomaly that warrants further investigation - and we are working with the UCI to resolve this matter. Meanwhile, we continue to be focused on delivering the best results during the World Track Championships."
Brailsford added on BBC Radio 5 Live: "I am sure there is an honest explanation.
"I am astonished and disappointed for Rob and frustrated for the team.
"But at the end of the day I think the truth will prevail as always. I welcome the screening system I think it is a great thing. I think we should be subject to it and I would like to see other nations subject to it."
"This is not the first time this has happened to several riders and you tend to find that there are subsequent tests that are then actually verified by the UCI. They come back and said everything is fine.
"I have known Rob a long time and there has never been any doubt in my mind that he has been anything but a fantastic athlete for Britain. He does not take drugs."
More news from SportingLife.com
