Presidential candidate Dana Rosemary Scallon has threatened to pull out of the presidential race if she continues to be questioned about her US citizenship.
Ms Scallon attacked the media for pursuing the revelations and said it was "too hurtful" to go over the details because they emerged from court records related to a family dispute.
"I will not answer any more questions about this, it's too hurtful," she said. "I spoke to my sister last night and I will not have my family dragged across this presidential election, or I will step out of it," she said.
Ms Scallon said she became a US citizen in October 1999 and would be prepared to renounce it if necessary on being elected to the Aras or if the people of Ireland wished her to do so.
But she insisted it was not a disadvantage and could even work in Ireland's favour.
Ms Scallon also hit out about being "grilled" by the media about what she said were divisive issues related to her views as a practising Catholic.
Citing constitutional protections of the unborn and marriage between a man and a woman, she said she was more in tune with the Constitution than the other candidates.
"Do not discriminate against me because I am a Catholic," she said during an interview on RTE Radio One's Today with Pat Kenny.
"I'm sick and tired of being grilled on issues where in fact I am perfectly in tune with the Constitution."
Ms Scallon said there was an anti-Catholic agenda and that she would always respect the will of the people.