The 28-year-old from Mullingar allegedly tested positve during an out-of-competition test at his training base in the United States last month.

Fagan represented Ireland at the 2008 Olympics in Beijing where he dropped out of the marathon at halfway.

He has failed to finish a marathon since, including at Chicago in the last mile last October when he appeared to be on course for a time well inside the qualifying time for London 2012 of 2 hours 15min. 

Fagan had next targeted today's Houston Marathon, which is being staged alongside the US Olympic marathon trial.

Athletics Ireland have refused to confirm the reports but have confirmed that an athlete has tested positive.

"Athletics Ireland can confirm that it has been advised of an alleged anti-doping rule violation by an Irish athlete following an adverse finding in a test taken in December last [2011]," a statement said.

"The matter will now be the subject of a hearing before the Irish Sport Anti-Doping Disciplinary Panel which is to be convened in the very near future.

"Under the Irish Anti Doping Rules, Athletics Ireland cannot comment further until the Panel concludes its work and its final determination has been issued." 

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