The Irish Sports Council has confirmed an "adverse analytical finding" in a urine sample provided 10,000m runner Cathal Lombard.
The Corkman today admitted using the banned substance EPO in a newspaper interview.
In a statement the Irish Sports Council said that the test had been conducted by the Swiss Olympic Association at it's request, and was done so for three reasons.
The statement reads: "Under criteria established by the Irish Sports Council, Cathal Lombard was target tested for three specific reasons. "Firstly, the athlete is supported by Council's International Carding Scheme. Secondly, he had been selected as part of the Irish Olympic team. Thirdly, he had shown dramatic improvements in performance in recent times."
Lombard (28) was informed on Saturday that a recent out-of-competition doping test had revealed traces of the substance erythropoietin (EPO), one of the more widely abused drugs in endurance sports.
"I didn't set out to try and win medals or to make money. I just wanted to be as competitive as I could and have an equal chance with everyone else," he told the Irish Examiner today.
"I am not trying to justify what I did in any way; I am just saying this was the case, this is what I did and, hands up, I did it."
He added that it is unlikely he will contest the test findings.
Lombard is due to travel home from Italy later today, where he had been completing his preparations for the Athens Olympics. As a result of the positive test, however, he is now certain to be pulled from the Irish team and the 10,000 metres event, in which he was due to compete next Friday week.
Lombard has agreed to meet officials from Athletics Ireland tomorrow to answer formally the charge of his failed drugs test, which was carried out in Switzerland last month while the athlete was training at St Moritz.
Lombard set an Irish 10,000 metres record in California earlier this year and finished 17th in the 10,000 metres final at the 2003 world championships.
Last night Athletics Ireland media spokesman Pierce O'Callaghan called for a public inquiry into the Lombard case to help clarify the exact nature of the problem of possible drug use in Irish sport.
"As a coach myself I think the public deserve to know what exactly went on in this particular case. I think we need to know who, where and what exactly was involved to make sure it doesn't happen again."