The Justice Department announced Wednesday that it will not attempt to retry former presidential candidate John Edwards on corruption charges.

The decision brings to a close an unusual and much-criticized campaign finance case against Edwards, who was acquitted of one count on May 31 by a jury in North Carolina that could not reach a verdict on five other counts.

“We knew that this case — like all campaign finance cases — would be challenging,” Assistant Attorney General Lanny A. Breuer of the Justice Department’s Criminal Division said in a statement. “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.”

Several Justice officials said the department decided it was not worth it to put any more resources into the expensive case.

Prosecutors had asked jurors to grasp a novel legal concept: that nearly $1 million paid by two wealthy benefactors to hide an extramarital affair during and shortly after Edwards’s 2008 presidential bid should be considered campaign donations that are subject to disclosure rules.

The prosecution dwelled for weeks on the tawdry details of the case: the child Edwards fathered with videographer Rielle Hunter and tried to conceal; the lies he told to friends, staffers and his wife, Elizabeth, who was dying from cancer; the luxury resorts and private planes used to keep Hunter happy and quiet.

In television interviews, several jurors said that they thought Edwards was guilty but that prosecutors failed to meet their burden to prove he knew about the payments. Some of the jurors also said they did not believe the testimony of the star prosecution witness, Andrew Young, a staffer who said Edwards persuaded him to claim paternity of the child as part of a byzantine coverup.

The defense team — Abbe Lowell, Allison Van Laningham and Alan Duncan — said in a statement: “As we stated in our motions and arguments in court, the novel theory of campaign law violations charged by the Justice Department is not a crime. It should be addressed, if at all, by the Federal Election Commission, which our evidence showed seems to have agreed with our views on the law.”

“While John has repeatedly admitted to his sins, he has also consistently asserted, as we demonstrated at the trial, that he did not violate any campaign law nor even imagined that any campaign laws could apply. We are confident that the outcome of any new trial would have been the same. We are very glad that, after living under this cloud for over three years, John and his family can have their lives back and enjoy the peace they deserve.”