EPO testing questioned after Australian runner Bol cleared of doping

Bol, who narrowly missed bronze when he finished fourth at the 2020 Tokyo Olympics, returned a positive result for performance-enhancing Erythropoietin Receptor Agonists (EPO) in January.

He was suspended from all competition, but a later analysis of his B-sample returned an "atypical finding", meaning it did not confirm the original test.

The Sudan-born athlete, who always claimed innocence, has now been cleared, with further testing at a World Anti-Doping Agency-accredited laboratory confirming a negative result

"As a result, Sport Integrity Australia has taken the decision not to progress an anti-doping rule violation for this sample," the anti-doping agency said. "The investigation into this sample is finalised."

Bol said he had been "exonerated" and would now focus on the World Athletics Championships in Hungary later this month.

"It was a false positive like I have said all along," he said.

"The news from Sport Integrity Australia today was a dream come true. No one should ever experience what I have gone through this year."

Athletics Australia said the matter raised serious questions about how EPO was analysed.

"Above all, Athletics Australia would like to express its full support for Peter and also its dismay that an innocent athlete has had his integrity put into question," AA chief Peter Bromley said.

"This case raises very serious questions about the accuracy and consistency of EPO analysis.

"Peter Bol has been trapped in a very difficult and damaging no-man's land for the last seven months.

"He, and every other high-performance athlete, deserves clear and transparent answers to explain what went wrong and what is being done to ensure it doesn't happen again."

WADA said in a statement it was satisfied that Sport Integrity Australia followed all applicable processes, but would conduct a review nevertheless.

"While we have no reason to question the validity of the analytical method used for recombinant EPO, WADA will assess the current review process in light of the particularities of this case," it said.