Lawyers for Sen. Ted Stevens (R-Alaska) have asked the Justice Department to launch a formal investigation into what they allege was misconduct by the prosecutors who pursued the case that ended in the Senator’s conviction Monday on seven criminal counts.

Stevens was found guilty of failing to disclose on his annual financial reports hundreds of thousands of dollars worth of gifts that he received, including major upgrades to his home provided by the oil services company VECO and its chief executive officer, Bill Allen.

In a letter sent to Attorney General Michael Mukasey on Tuesday, attorney Brendan Sullivan recounts a series of disputes that erupted during the trial, which became the basis of several motions to dismiss the case. Sullivan argues in the letter — as he did during the trial — that the Justice Department’s prosecutors withheld evidence that could have been helpful to the defense, provided evidence during the trail that it knew was false, and elicited damning statements from Allen during the trial that he did not appear to make at any time before the trial.

Judge Emmet Sullivan rejected the dismissal motions that included these allegations, but he repeatedly chided the government for failing to turn over to the defense all the evidence that it was required to provide. The judge ultimately struck from the trial record evidence related to the hours that two VECO employees worked on Stevens’ home, based on the discovery that the government knew that two of those employees were not working on the Stevens’ job for significant periods of time that VECO’s records indicated they were.

Brendan Sullivan argued during the trial — and repeated in Tuesday’s letter — that Allen’s testimony that he was told by Stevens’ friend Bob Persons that the Senator was merely “covering his ass” when he asked for bills appears to have been fabricated. Sullivan argued that Persons testified that he never said that, and that the government never asked him about it in any pretrial interviews. Sullivan’s letter points out that Allen’s recollection of this conversation does not appear on any of “more than 50 government memoranda … relating to Mr. Allen that were eventually provided to the defense.”

Sullivan told Mukasey that “the misconduct in this case was repeated, severe, intentional and inexcusable,” and argued that “the Department should immediately commence a formal investigation into the misconduct in this case.”

Since the verdict, Stevens’ campaign has sent out statements emphasizing his view that the prosecution was unjust and indicating that he will appeal the convictions on these same grounds.

Sullivan’s letter makes no mention of the fact that the prosecution team announced during the trial that they had referred themselves to the department’s Office of Professional Responsibility for an investigation into their mishandling of evidence in the case.

A Justice Department spokeswoman declined to comment.