The information about the potential scheme was included in an opinion, dated Aug. 28, from the chief United States district judge for the District of Columbia, Beryl A. Howell, who was weighing whether to allow federal prosecutors to examine evidence like emails that may have been protected by attorney-client privilege.
Judge Howell granted the prosecutors access to the materials.
Investigators suspected that the convict seeking the pardon was imprisoned as recently as this summer and that two people working on behalf of the convict may have undertaken a secret lobbying campaign by approaching White House officials, according to the documents.
The two people may have offered to funnel money as political donations in exchange for the pardon or commutation, although it was unclear where the money was supposed to be sent.
Given Mr. Trumps undisciplined approach to pardons, the disclosure, coming amid a flurry of reports about how Mr. Trump has been discussing whether to pardon his children and close confidants in the final weeks of his presidency, raised fears that the pardon process may have been corrupted.