Italian cyclist Luca Paolini has been expelled from the Tour de France after testing positive for cocaine.
The 38-year-old Katusha rider failed the test on Tuesday - after the fourth stage from Seraing to Cambrai - and has been provisionally suspended.
He can now request a B sample and his provisional suspension will last until the hearing of his case.
In a series of posts on his Twitter account, Paolini apologised and said he takes "full responsibility".
"Sorry to all my fellow riders," he added. "I have always believed in testing because they are making this sport ever more credible. I want to remain silent and resolve my issues.
"I know this is a bad time, above all because of the intense media scrutiny. I hope my absence doesn't hinder our chances of a good final result."
Paolini was 168th overall and his exit takes the number of riders on the Tour to 185. He was taking part in his fifth Tour, primarily supporting Katusha's Norwegian sprinter Alexander Kristoff.