WASHINGTON (CNN) -- Federal prosecutors dropped the remaining charges against former Democratic presidential candidate John Edwards on Wednesday, less than two weeks after his corruption trial ended in an acquittal and mistrial.

The Justice Department had accused Edwards of using nearly $1 million in illegal campaign contributions to keep his pregnant mistress under wraps as he mounted a second presidential bid in 2008. But after more than 50 hours of deliberation, a North Carolina jury acquitted him on one of the six counts against him and deadlocked on the other five.

"We knew that this case -- like all campaign finance cases -- would be challenging," the head of the Justice Department's criminal division, Lanny Breuer, said in a written statement on the decision. "But it is our duty to bring hard cases when we believe that the facts and the law support charging a candidate for high office with a crime."

Edwards' lawyers said in a statement, "We are confident that the outcome of any new trial would have been the same."