Great Britain?s Robert Hayles and Holland?s Pim Ligthart will not be allowed to ride in the track world championships in Manchester after failing pre-race blood tests.
The two riders both resulted over the 50% blood haematocrit level and so have automatically been suspended for two weeks.
Hayles was due to ride the individual pursuit event on Wednesday and the team pursuit on Thursday. Pim was entered for Friday?s men?s points race.
A total of 66 tests were carried on riders from the USA, Australia Holland and Great Britain teams on Wednesday day morning. All the other riders were cleared to race.
British Cycling defended Hayles, explaining that his test was just 0.3% over the 50% limit.
?We are totally supportive of the screening system,? Dave Brailsford, British Cycling performance director said in a statement.
?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 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.?