Washington, D.C. ? Faced with embarrassing revelations about withheld evidence, the Justice Department on Wednesday moved to reverse the conviction of former Alaska Sen. Ted Stevens, who lost his bid for re-election just days after a jury found that he had lied about gifts and home renovations.

Justice Department lawyers asked a judge to dismiss the indictment against Stevens and toss out his conviction — effectively killing their own courtroom victory with a shocking admission of misbehavior by prosecutors.

The Stevens case, the government’s highest-profile attack on congressional corruption in recent years, was plagued by problems that continued to pile up even after a jury found him guilty. The last straw, apparently, was the failure of prosecutors to turn over notes of a crucial interview in which a witness contradicted a statement he made later under oath at trial.