Orica-GreenEdge rider Impey fails drugs test
Daryl Impey, who last year became the first South African to wear the Tour de France yellow jersey, has failed a drugs test.
Orica-GreenEdge rider Impey tested positive for the banned substance Probenecid at the South African championships in February.
He has been suspended by his team for this year's Tour, which gets underway in Yorkshire on Friday.
"I am extremely distressed by the finding, as I have always raced clean throughout my career," Impey said. "I remain confident I will be vindicated and proved innocent of any wrongdoing. Every result I have achieved to date has been because of hard work and dedication on my part."
Impey's place in the Orica-GreenEdge squad is taken by 21-year-old British rider Simon Yates. Impey won the yellow jersey, worn by the overall leader, on stage six of last year's Tour - wearing it for two days.
In a statement, Orice-GreeEdge said: "[We] have been notified that Daryl Impey has returned an adverse analytical finding and has been notified by the South African Institute for a Drug-Free sport that he delivered a positive A and B sample for the substance Probecenid after the South African Championships on February 6, 2014.
"The team would like to underline that it respects Daryl Impey's right to prove his full innocence and will not comment any further until the process has run its due course and final conclusion has been made.
"As per the team's code of conduct, Daryl Impey will not feature on the team's roster until the case has been closed and he is fully eligible to ride."