Australia-based Orica-GreenEDGE released a statement on Wednesday saying it was notified by the South African Institute for Drug-Free Sport that the 29-year-old cyclist had delivered a positive A and B sample to the banned masking agent Probenecid after the South African Championships on February 6.
Impey became the first African rider to wear the Tour de France’s yellow jersey last year when he led the standings during stages six and seven.
This year’s Tour starts on Saturday in Leeds, England.
“Impey will not feature on the team’s roster until the case has been closed and he is fully eligible to ride,” Orica-GreenEDGE said.
Impey said he had no knowledge of Probenecid and had never knowingly taken the substance.
“I am committed to drug-free sport and fully intend to take all steps necessary to clear myself of any suspicion,” he said. “I immediately flew back to South Africa and was present at the analysis of my B sample on June 27, the results of which confirmed the initial analysis.” – Sapa-AP