"Get a doctor to fake the DNA results," Young said Edwards told him. "And he asked me and Cheri to steal a diaper from the baby so he could secretly do a DNA test to find out if this [was] indeed his child."
Young said he ignored the request.
John Edwards has had little to say about the fresh revelations. Asked to comment while in Haiti Thursday, Edwards said only, "I've said what I have to say for now, and I'm here to help people."
Elizabeth Edwards told The Associated Press "the whole family is relieved" by her husband's admission of his paternity.
She did not answer questions about their marital status and would not say where they will go in the future. "If somebody has a crystal ball, they can let me know," said Edwards, who is still fighting breast cancer. "My marriage shouldn't be on anybody's radar screen except mine."
Edwards' admission this week caps a long string of blatant denials. Edwards at first denied reports in the supermarket tabloid the National Enquirer that he had had a fling with Hunter. After admitting to ABC News' Bob Woodruff that he had lied about the affair, he adamantly denied that he was the father of her baby and said he would welcome a paternity test.
It wasn't until Thursday that Edwards finally publicly admitted that he had fathered Quinn. Edwards has three children with his wife, Cate, 27; Emma, 11; and Jack, 9.
Mark Halperin, the co-author of a book that came out earlier this month called "Game Change," has also leveled allegations of bizarre behavior by John and Elizabeth Edwards, as well as other candidates.
Halperin noted that Edwards is under pressure because a federal grand jury is looking into whether payments Edwards' presidential campaign made to Hunter after she stopped working as the campaign's videographer were illegal payments. Young has testified before that grand jury.
Halperin said that Edwards was in a complicated situation, facing "legal jeopardy," negotiating child support for Quinn, getting slammed by two new books, and increasingly under pressure from Hunter to come forward and claim paternity.
"It's probably best for him to stay quiet until he sees where the grand jury investigation is going," Halperin said.
He said Elizabeth Edwards has been a force in her husband's public acceptance of paternity.
"She's come to terms with it," Halperin said. "She wants her husband to do the right thing. Now that she's accepted that it's his child, I think it's important to her that the child have a father, that John Edwards step up and to the right thing."
The author said that, as he reported in "Game Change," that Edwards was negotiating with then-Democratic nominee Barack Obama during the early stages of the scandal to be his vice presidential running mate. When that didn't pan out, Edwards sought to be appointed Obama's attorney general, Halperin said.
"This is not a guy who gives up political opportunity easily," Halperin said.
Edwards' friend David Kirby said Edwards still has a future.
"I know this man can rise from the ashes," Kirby said.
Halperin, however, said it's unlikely Edwards can return to elective politics.
"I think it's impossible," he said.