The pages had been withheld from the trove of documents related to the convicted sex offender Jeffrey Epstein because of what officials called a mistaken determination that they were duplicates.
The Justice Department acknowledged on Thursday that it had also identified about a dozen other documents that were “incorrectly coded as duplicative.”
The actions of Ms. Halligan, who as a U.S. attorney brought criminal cases against President Trump’s enemies, are under review by the organization that licensed her to practice law.
Prosecutors in the U.S. attorney’s office in Washington were unable to build a case, underscoring the department’s increasing inability to follow through on the president’s desire to indict his rivals.
Former President Joseph R. Biden Jr. has forcefully denied assertions that his use of the autopen broke the law, calling President Trump and his allies “liars.”
The administration has no control over the disciplinary authorities of state bar associations, but a new proposal would let the attorney general ask them to suspend proceedings involving department lawyers.
The administration told a court on Monday that it was abandoning its defense of executive orders targeting the firms. But on Tuesday, the Justice Department abruptly changed its position.