Martin Fagan has been banned for two years for his use of performance enhancing drugs.
The Mullingar runner has admitted taking the banned substance EPO and faced an anti-doping committee in Dublin on Tuesday evening.
The 28-year-old revealed that he bought the drug on the internet and administered it himself in a bid to win last weekend's Houston marathon.
Fagan's failed test was taken in December.
A committee statement reads: “Athletics Ireland and the Irish Sports Council jointly announce that the Irish Sport Anti-Doping Disciplinary Panel has determined that Martin Fagan, an athlete affiliated to Athletics Ireland, has committed an anti-doping rule violation.
“The Panel found that, contrary to Article 2.1 of the Irish Anti-Doping Rules, Mr Fagan, tested positive for the presence of a prohibited substance or its metabolite or marker, recombinant erythropoietin, in a sample of his urine collected on behalf of the Irish Sports Council during out of competition testing at Tucson, Arizona on the 10th December 2011.
“Mr Fagan has been sanctioned, subject to his right to appeal within 14 days, by the imposition on him of a period of ineligibility for two years. The Panel has decided that because of the prompt admission of the violation by Mr Fagan the appropriate commencement date for the period of ineligibility is 10th December 2011, the date on which the sample was collected.
“The hearing was held under Article 8 (Disciplinary Process) of the Irish Anti-Doping Rules and this announcement is made pursuant to Article 15 (Public Disclosure) of the Rules.”