A federal grand jury indicted two-time presidential candidate John Edwards on Friday over massive sums of money spent to keep his mistress in hiding during the peak of his 2008 campaign for the White House.

He was scheduled to be arraigned later in the day in Winston-Salem, N.C.

Edwards initially denied having an affair with Rielle Hunter but eventually admitted to it in the summer of 2008. He then denied being the father of her child before finally confessing last year. His wife, Elizabeth, died of cancer in December.

The case of USA v Johnny Reid Edwards contains six counts: one count of conspiracy, four counts of illegal campaign contributions and one count of false statements. The indictment was returned in the Middle District of North Carolina.

Edwards could face five years in prison if convicted.

The indictment was the culmination of a federal investigation that lasted more than two years and scoured through virtually every corner of Edwards’ political career.

It said Edwards proposed the names of wealthy donors who could give his mistress and their baby financial support. The money paid for hotels, chartered airplanes and living expenses. And none of it was reported to federal election officials.

The indictment said the payments were a scheme to protect Edwards’ White House ambitions. “A centerpiece of Edwards’ candidacy was his public image as a devoted family man,” the document read.

“Edwards knew that public revelation of the affair and the pregnancy would destroy his candidacy by, among other things, undermining Edwards’ presentation of himself as a family man and by forcing his campaign to divert personnel and resources away from other campaign activities to respond to criticism and media scrutiny regarding the affair and pregnancy,” the indictment added.

Edwards’ lawyer Gregory Craig issued a statement saying Edwards “is innocent of all charges, and will plead not guilty.”

Defense attorneys also issued statements from campaign finance experts advising him.

The experts argued the payments provided by two wealthy Edwards supporters — his former campaign finance chairman Fred Baron and Rachel “Bunny” Mellon, the 100-year-old widow of banking heir Paul Mellon — were not campaign contributions. One, former Federal Elections Commission Chairman Scott Thomas, said if the FEC had investigated it would have found the payments did not violate the law, even as a civil matter.

“A criminal prosecution of a candidate on these facts would be outside anything I would expect after decades of experience with the campaign finance laws,” Thomas said.

NPR’s Carrie Johnson reported from Washington, D.C., for this story, which contains material from The Associated Press.

Copyright 2011 National Public Radio.