Britain's cycling director Dave Brailsford admitted on Wednesday the world track cycling championships had begun under a cloud after endurance rider Rob Hayles failed a blood screening test.
Britain are the team to beat at the championships, which they dominated last year in Spain, and are considered track cycling's global pacesetters five months ahead of the 2008 Olympics in Beijing.
Their bid to get off to a positive start here on Wednesday however hit the skids when both Hayles and Dutch rider Pim Ligthart failed routine blood screening tests.
A total of 66 riders from four teams were subject to the tests by the International Cycling Union (UCI).
Hayles has now been temporarily suspended for 14 days after the volume of red blood cells in his blood (haematocrit) was found to be over the UCI's permitted threshold of 50 - an indication, though not proof, of blood manipulation.
In accordance with UCI rules Ligthart was also suspended. His team have claimed his haematocrit level was not above 50, but that instead other, crucial parameters aroused suspicion with UCI officials.
A British team spokesman confirmed to AFP that Hayles' haematocrit level was at 50.3, while Brailsford - who is Britain's Cycling Performance Director said in an earlier statement he did not suspect Hayles.
"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," he said.
"Indeed we have had riders in the past who have recorded such anomalies during screening and which have been proved to be entirely normal."He later admitted he had to tell Hayles of the news, and said the 35-year-old Englishman was devastated.
"He heard the news from me and he was absolutely devastated," Brailsford said later. "It's harsh, when you have to phone home and tell the missus what's happened - that's a hard phone call to make."
Brailsford said Hayles, who won his first world championship medals in Manchester eight years ago in the pursuit (bronze) and team pursuit (silver), had naturally high haematocrit levels.
"It's relatively high, it always has been."
He said the British team will now work alongside the UCI to determine the cause of Hayles' result, and said they will take the necessary action if required.
"At this moment in time I think it's important for everyone to take a look at the situation. We'll supply all the data we have, and we have a lot. Rob was last tested on March 4, and he's been tested hundreds of times throughout his career," added Brailsford.
"We just want to establish the facts, and we will react based on that rather than speculation and opinion."
However, with Britain in the track spotlight after winning seven gold and 11 in total at last year's competition, Brailsford said the news had been unwelcome.
"It's the opening day of the worlds, and it's not what we want."