RALEIGH, N.C. - The Justice Department plans to bring criminal charges against John Edwards after a two-year investigation into whether the former presidential candidate illegally used money from some of his political backers to cover up his extramarital affair, a person familiar with the case said Wednesday.

An indictment could come within days unless the 2004 Democratic vice presidential nominee reaches a deal with prosecutors to plead guilty to a negotiated charge, said the person, who spoke on condition of anonymity because of the case's sensitivity. It was not immediately clear what charges prosecutors planned to bring.

Federal authorities have been investigating the former North Carolina senator's campaign finances, focusing on money from wealthy supporters that allegedly went to keep mistress Rielle Hunter and her out-of-wedlock baby in hiding in 2007 and 2008 to protect Edwards' White House campaign from a career-ending scandal.

Prosecutors, in an investigation overseen by Justice Department officials, have been looking at whether those funds should have been reported as campaign contributions since they arguably aided his presidential bid.

Edwards attorney Gregory Craig said that prosecutors had never found that campaign funds were misused and that the government's theory in the case was "wrong on the facts and wrong on the law."

The inquiry has centered largely on allegations leveled by former Edwards campaign aide Andrew Young, who as the scandal began to unfold in 2007 publicly claimed to be the baby's father to protect his boss.

Young has said that two wealthy Edwards supporters supplied the money and the private jet that Young used to hide Hunter from the news media, first in North Carolina, then in Colorado, and finally at a home in California.

Hunter had been hired to shoot video of Edwards as he prepared for his White House bid. Their child was born in February 2008, a month after he dropped out of the race. Edwards initially denied having an affair with Hunter but eventually admitted to it in the summer of 2008. He also denied being the father of her child before confessing last year. His wife, Elizabeth, died of cancer in December.

Edwards, 57, who made his millions as a trial lawyer, could lose his law license if he enters a guilty plea.

Young has said that Edwards agreed in 2007 to solicit money directly from Rachel "Bunny" Mellon, the 100-year-old widow of banking heir Paul Mellon. Young has said he received hundreds of thousands of dollars in checks from Mellon for his use and Hunter's, with some of the checks hidden in boxes of chocolate.

Mellon's attorney has said she didn't know where the money was going but intended it as a personal gift.

Investigators also looked at money spent by Edwards' former campaign-finance chairman, Fred Baron, who died in 2008. He said he helped Young and Hunter move across the country. Baron said that Edwards wasn't aware of the aid.