RALEIGH, N.C. — A former aide to John Edwards is reportedly writing a book in which he claims the former presidential candidate and U.S. senator fathered the child of a woman with whom he's admitted an affair.

Various media outlets have reported that Andrew Young, a longtime friend of Edwards, is writing the book, which makes the claim and could provide further insight into the story that has captured national headlines and sparked a federal investigation.

Neither representatives for Young nor St. Martin's Press, the publishing company believed to have signed Young, would comment Monday.

Wade Smith, a Raleigh attorney representing Edwards, also had no comment.

Allegations surfaced in late 2007 that Edwards, had an affair with Rielle Hunter, a videographer for his campaign, that she became pregnant and had a child. No father is listed on the girl's birth certificate.

Edwards repeatedly denied the claims until last summer when he admitted to an affair with Hunter in 2006. He has continued to deny paternity, saying the affair ended before the infant girl, born in February 2008, was conceived.

Elizabeth Edwards, who has incurable cancer, has said in interviews that she doesn't know if her husband is the child's father.

Young stepped in last year to claim paternity. According to The New York Daily News, which reported the book deal Sunday, he agreed to do so because "his belief in Edwards ran so deep" and that he invited a pregnant Hunter to live with his family.

Later, Young and his family moved to a home in California, and while unpacking, he found a video tape of Edwards and Hunter having sex, the Daily News reported.

Joe Sinsheimer, a former Democratic Party consultant, believes Edwards needs to do more explaining.

"What he is not realizing is – that that by him not coming out and answering questions—is that this will haunt him for the rest of his life," Sinsheimer said.

Federal investigators are also now looking into whether Edwards used campaign funds to pay others to keep quiet about the affair. Edwards has said he is confident that none were used improperly.

Fred Baron, who served as national finance chairman in Edwards’ presidential election campaign, said last year that he quietly began sending money to Young and Hunter but that no campaign funds were used and that Hunter was not working for the campaign when he started giving her money.

Any account from Young could also interest federal investigators, Sinsheimer said.

"To date, we know that Fred Baron paid Rielle Hunter and Andrew Young," he said. "We don't know if other funds were used, and I would think investigators would be most interested in that."

Meanwhile Hunter's longtime friend, Pigeon O'Brien said Monday that she is happy that there might be a book.

"I don't think anybody had a clear perspective on what actually happened, given that, I think, the Edwardses have controlled a lot of what people think the record is now," O'Brien said.