Judge Emmet G. Sullivan, who presided over the Stevens trial in Federal District Court here, has called a hearing Friday to consider a request by Mr. Stevens’s lawyers for a new trial based on Mr. Joy’s complaint, which was filed with the Justice Department as part of a procedure to obtain whistleblower status, which would protect him against job-related retaliation.

Image An F.B.I. agent has questioned a colleagues relationship with Bill Allen, who testified at the trial of Ted Stevens, above. Credit... Brendan Smialowski for The New York Times

Mr. Stevens, an Alaska Republican who lost his campaign for re-election in November, is awaiting sentencing after his conviction on charges involving failure to list on his Senate disclosure form goods and services he obtained from several supporters, but mostly from Mr. Allen, an influential oil-services tycoon in Alaska and a onetime close friend.

Mr. Stevens’s trial was punctuated by errors by prosecutors, which brought serial scoldings from Judge Sullivan. At the time, the chief prosecutor, Brenda Morris, repeatedly apologized for the errors, insisting to Judge Sullivan that they were mistakes of inadvertence and negligence but were not purposeful.

Mr. Joy’s statement, however, directly contradicts Ms. Morris’s assertions.

“I have witnessed or learned of serious violations of policy, rules, and procedures as well as possible criminal violations,” Mr. Joy wrote in the affidavit sent to the Justice Department that is now part of the court file.

For example, a witness for both the government and defense, Rocky Williams, was sent home to Alaska by prosecutors who did not tell defense lawyers, an act that angered Judge Sullivan. Ms. Morris said the decision was made because Mr. Williams was gravely ill, not because prosecutors, after interviewing him, had decided he might help the defense case.