Daryl Impey positive for Probenecid

Daryl Impey, the first African to wear the Tour de France's yellow jersey, has tested positive for banned drug Probenecid, according to a team Orica-GreenEdge statement on Wednesday morning.

Orica did not name the 29-year-old South African on its Tour de France team yesterday, one year after his yellow jersey ride, and has withdrawn him from competition as the case develops.

The Australian team's statement read: "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 Probenecid after the South African Championships on February 6, 2014."

Impey won the time trial and placed second in the road race at the national championships. He last raced at the Critérium du Dauphiné two weeks ago where he finished 89th overall.

Probenecid can be used as a diuretic and a masking agent. The 1988 Tour de France winner, Spain's Pedro Delgado tested positive for the drug but was later cleared and kept his title.

Orica named five Tour de France debutants in its team yesterday, including British neo-pro Simon Yates. Now it begins the Tour de France the way it ended last year, under a dark cloud. Stuart O'Grady retired from cycling at the end of the Tour last and three days later admitted to doping in 1998.

"I confirm that on 23 June 2014, I was notified by William Newman, the President of Cycling South Africa, about an adverse analytical finding for Probenecid," said Impey in a statement.

"I had no knowledge of Probenecid nor have I ever taken the substance knowingly in any manner. I am committed to drug-free sport and fully intend to take all steps necessary to clear myself of any suspicion.

Impey added that the news "came as a complete shock" in the days before the start of the Tour de France. He flew from his European base in Monaco back to South Africa after he heard about the finding.

"I am extremely distressed by the finding, as I have always raced clean throughout my career," he said. "Every result that I have achieved to date has been as a result of hard work and dedication on my part."

Simon Yates to make Tour de France debut with Orica-GreenEdge