Reports of inconclusive or subjective analysis in the positive doping case of Irish sprinter Steven Colvert have been described as "unchallenged theoretical objections" and "a charge against skilled, experienced scientists".

Professor Christiane Ayotte, director of the Wada-accredited laboratory in Montreal and president of the World Association of Anti-Doping Scientists (Waads), believes the analysis of Colvert's doping sample was consistent with the presence of recombinant (synthetic) EPO, the banned blood-boosting drug.

Colvert tested positive back in May of 2014, and despite repeatedly declaring his innocence was handed a two-year ban by an Irish Sports Council Disciplinary panel. That ban has expired, and Colvert, now 26, is free to compete, although he continues to go to considerable lengths to clear his name.

Earlier this month, his case was quoted by a group of Norwegian scientists in the medical journal Lab Times, who raised concerns about the Wada anti-doping procedures and interpretation which resulted in Colvert’s positive test, suggesting his case should have been dropped.

According to Ayotte, who has worked in anti-doping since 1991 and is considered one of the leading experts in the field, the Norwegian report is a "one-sided vitriolic opus", and instead, with "no hesitation", she gives her support to the both the Wada-accredited laboratory in Cologne, Germany and the Wada-accredited lab in Seibersdorf, Austria who carried out the original analysis of the Colvert sample (a second opinion, in all positive cases, is mandatory).

“This article is the second one presenting the views of a group of scientists who are not only challenging the interpretation of an athlete’s EPO test results, but discrediting ‘WADA’s credibility, again’,” says Ayotte, in reference to Lab Times. “While it may sound seemingly insignificant to refer to ‘WADA’s credibility’, this one-side vitriolic opus is a charge against skilled, experienced scientists. It is worth noting that the four signatories never submitted any data in support to their position; they opted instead for voicing unchallenged theoretical objections, in a magazine.

“The laboratory in Cologne tested Mr Colvert’s A- and B-samples five times with the two recognized and widely applied complementary techniques (SAR-PAGE and IEF); each time the results were consistent with the presence of a recombinant EPO.

“The criteria for reporting an adverse analytical finding were objectively met and the conclusions reached by the laboratory were supported from the independent review made by the experts of a second laboratory located in Austria. The scientists from these two organizations have published on EPO testing, their expertise is recognized. Each time Mr Colvert’s samples were analysed, the mixed recombinant and endogenous populations were revealed by the diffuse and faint area above the corresponding signal of endogenous EPO indicating the presence of recombinant EPO.

“These profiles depart significantly from human urinary endogenous EPO. Both the (IEF and SAR-PAGE) test results are evidence for the presence of a recombinant EPO in Mr Colvert’s A- and B-samples. With no hesitation, I support the conclusions of my colleagues from Cologne and Seibersdorf.”

Ayotte's comments have already been perceived by some as merely defending her own field: as president of Waads, she represents the 35 Wada-accredited laboratories and its 150 members, most of who work full-time in anti-doping. She's also been called onto Wada's independent commission to examine the allegations of anti-doping malpractice at the 2014 Sochi Winter Olympics.

The Lab Times article wasn't alone, however: among those to also question the findings of Colvert's doping case was South African sports scientist Ross Tucker, who in an article published this week, concluded that the original analysis wasn't enough to say that he didn't commit a doping offence, "but there's no legal, or scientific basis, to say that he did, either".

Colvert, in the immediate aftermath of his positive test, suggested the testers may have mixed up his sample with someone else, although this was ruled out on examination of the B-sample. He admitted he had taken a generic multivitamin and an iron supplement in the days before the test, although there is little evidence of a positive test for recombinant (synthetic) EPO being caused by a contaminated supplement, given it is most commonly administered by injection.

Given his original doping sample is long since destroyed, it may be now be that Colvert’s case will be forever open to interpretation.