WASHINGTON — A special counsel testified Wednesday that overzealous U.S. prosecutors were so intent on winning a corruption case against the late Sen. Ted Stevens that they intentionally withheld information they were obligated to give the defense.

Henry Schuelke III told the Senate Judiciary Committee that high-level officials in the Justice Department’s public integrity section failed to supervise the prosecution team, also a factor in the botched case that led a judge to dismiss Stevens’ conviction.