Weil Gotshal & Manges sign logo. Photo: Jason Doiy/ALM

The former national sales director of opioid medicine manufacturer Insys Therapeutics, seeking a new trial, has accused his ex-defense lawyers at Weil, Gotshal & Manges of hiding a conflict from him because their firm is also working on Insys’ bankruptcy.

Richard Simon was one of five Insys executives convicted in Boston federal court of racketeering over the company’s payments to doctors, allegedly in exchange for prescribing its super-potent painkiller Subsys to patients who didn’t merit it. He and his co-defendants sought a new trial earlier this year, claiming the evidence against them was weak and misunderstood by jurors.

On Monday, however, Simon went further, saying it had become apparent that his lawyers at Weil had a conflict they didn’t tell him about. While supposedly defending him, Simon said, Weil advised Insys with its pending bankruptcy as the company helped the government investigate its former executives, including Simon.

Even though Covington & Burling was advising Insys on criminal and civil matters, the company’s dealings with prosecutors were “inextricably” linked to its bankruptcy, Simon argued.

“On information and belief, these complex financial agreements must have been reached as part of Insys’s long-running effort to resolve its own criminal case, which included cooperating in Mr. Simon’s criminal case and that of his co-defendants,” wrote Simon’s new lawyers at Fick & Marx.

U.S. District Judge Allison Burroughs of the District of Massachusetts on Tuesday partly granted his motion to submit supplement arguments seeking a new trial. She gave Simon through Sept. 9 to file a brief with more details.

In a statement, a Weil representative said at no point was the firm representing adverse interests and said Simon was aware of its work for Insys “at the outset.”

“In addition, Weil did not provide any advice to Insys or communicate with its other legal counsel with respect to whatever cooperation Insys provided to the Department of Justice in connection with the deferred prosecution agreement,” the statement continued.

Daniel Marx, a lawyer at Fick & Marx who is representing Simon, declined to comment.

The criminal case against Simon and other Insys executives, including CEO John Kapoor, has been closely watched. Prosecutors accused the defendants of pushing off-label uses of Subsys, which was approved to treat intense, so-called breakthrough cancer pain, in a way that was no different that drug dealers on street corners. They said the convictions they secured struck a blow against the opioid epidemic that has ravaged much of the U.S.

One piece of evidence that received widespread media coverage was an Insys sales video that featured a man dressed up as a Subsys bottle and employees of the company rapping about increasing high-dose prescriptions.

The original motion for a new trial and acquittal filed by Simon and his co-defendants is still being briefed, with final papers set to be filed by Aug. 30.