Australian Olympian Peter Bol tests positive for banned substance

The middle distance runner returned an adverse finding for synthetic erythropoietin (EPO) in an out-of-competition urine test last October and was suspended on Jan. 10 after the approval of Sports Integrity Australia.

Bol protested his innocence in a statement on his Twitterfeed on Friday and said he would be exercising his right to have the backup "B" sample tested.

"It is critically important to convey with the strongest conviction that I am innocent and have not taken this substance as I am accused," he wrote.

"To be clear I have NEVER in my life purchased, researched, possessed, administered or used synthetic EPO or any other prohibited substance."

EPO increases red blood cell mass, which allows the body to transport more oxygen to muscles and therefore increase stamina and performance.

Under the World Anti-Doping Agency code, Bol faces a ban of up to four years if he is found guilty of using a banned substance.