Canadian star cyclist Ryder Hesjedal says he "chose the wrong path'' after reports suggesting he was involved in doping emerged Wednesday.
Excerpts from a new book by former Danish rider Michael Rasmussen say Hesjedal was shown how to use performance-enhancing drugs at the start of his career.
Hesjedal said in a statement that the "mistakes'' happened more than 10 years ago when he was still a mountain biker and they were short-lived.
Hesjedal did not explicitly say he took performance-enhancing drugs, but in the contrite statement he apologized "for my part in the dark past of the sport.''
"I will always be sorry,'' he said.
Excerpts of Rasmussen's autobiography "Yellow Fever'' released in Danish newspaper claim that he taught Hesjedal how to use EPO, a banned substance used in blood doping.
Rasmussen admitted to using performance-enhancing drugs throughout most of his career in January.
Hesjedal won the Giro d'Italia last year to become the first Canadian to win a major European tour event.