A draft report from an internal Justice Department investigation alleges misconduct in the corruption trial of the late Sen. Ted Stevens (R-Alaska), the Associated Press reported Tuesday, citing an anonymous lawyer familiar with the matter.

The Office of Professional Responsibility’s investigation makes misconduct findings against prosecutors Joseph Bottini and James Goeke and FBI agent Mary Beth Kepner. Other department prosecutors involved in the case were not found to have engaged in misconduct.

The office is studying the failure by prosecutors to turn over evidence to defense lawyers, which led U.S. District Judge Emmet Sullivan to throw out Stevens’ convictions in April 2009 at the request of Attorney General Eric Holder. The Senator was convicted in October 2008 and died in a plane crash in August 2010.

National Public Radio first reported on the investigation.

Separately, the AP source said that an attorney brought in by Sullivan is determining whether the prosecutors on the trial team should be held in criminal contempt of court. Lawyer Henry Schuelke is trying to wrap up his work by year’s end, the source said.

The source said Schuelke had not made a decision about whether to recommend issuing charges, but NPR’s report said Schuelke would not recommend prosecution.