[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2008/POLITICS/08/09/lkl.edwards.affair/art.davidperel.cnn.jpg caption="National Enquirer editor-in-chief David Perel says the tabloid broke news of John Edwards' affair in 2007."]
(CNN) - Former North Carolina Sen. John Edwards admitted Friday to having an extramarital affair in 2006 with a woman who worked on his campaign.
Edwards has denied being the father of the woman's child, as had been alleged in tabloid reports, and it is willing to take a paternity test.
Wolf Blitzer, filling in for Larry King, spoke with David Perel, editor-in-chief of the National Enquirer, who originally broke the story in October 2007. Blitzer also spoke with Alan Butterfield, a senior reporter for the National Enquirer who confronted John Edwards at a hotel in Beverly Hills on Thursday.
Wolf Blitzer: What got you guys going in this direction to begin with?
David Perel: We received what we thought was a credible tip, Wolf, and we started investigating it. A lot of times when we go down this road and the story turns out not to be true, we abandon it. But the more we dug in, the more information The Enquirer uncovered that was standing up, we were able to prove that, indeed, John Edwards had a sexual affair with Rielle Hunter. We first did the story in October without naming her and then we came back with a much tougher story in December 2007, where we not only named her, but we photographed her pregnant.
Blitzer: And at that time, you didn't report that - what you reported subsequently, that you thought that he was the father.
Perel: That's true. We know that Rielle believes that he is the father. And Mr. Edwards today, in his own statement, said he did not take a paternity test. He's now saying that he will take one. We've asked him for months if he would take one and he's ignored that request.