Danish cyclist Michael Rasmussen, who quit the 2007 Tour de France when he was wearing the race leader's yellow jersey, admitted Thursday that he had used banned drugs between 1998-2010.
Rasmussen, a renowned climber who added that he was now retiring from the sport, said he had used the blood-booster EPO, growth hormones, testosterone, insulin and cortisone, as well as receiving blood transfusions.
"I used doping products and methods from 1998 until 2010," Rasmussen told a press conference, refusing to name who had collaborated with him.
The Danish sports confederation has opened an investigation and the 38-year-old Rasmussen said he would now work with the competent authorities to "thoroughly clean things up".
Rasmussen, who won four individual stages on the Tour de France, said he was ready to accept any ban he risked by coming clean, a decision he said had left him a "relieved man".
The move was a "definitive break with the past", said the sporting director of his Christina Watches-Onfone team, Claus Hembo.
"We want to take the initiative and encourage riders who doped to come forward," Hembo said.
Rasmussen was thrown off the 2007 Tour de France by his then-team Rabobank while wearing the yellow jersey for lying about his whereabouts the previous month when he was being sought out for doping tests.
He was subsequently banned for two years until July 2009 by world cycling's governing body, the UCI.