The Justice Department is investigating whether there was a secret scheme to lobby White House officials for a pardon as well as a related plot to offer a hefty political contribution in exchange for clemency, according to a court document unsealed Tuesday.

Most of the information in the 18-page court order is redacted, including the identity of the people whom prosecutors are investigating and whom the proposed pardon might be intended for.

But the document from August does reveal that people are suspected of having acted to secretly lobby White House officials to secure a pardon or sentence commutation and that, in a related scheme, a substantial political contribution was floated in exchange for a pardon.

As part of the investigation, more than 50 laptops, iPads and other digital devices have been seized, according to the document.

The existence of the investigation was revealed in a court order from U.S. District Judge Beryl Howell, the chief judge of Washington’s federal court, in which she granted investigators access to certain email communications connected to the alleged schemes that she said was not protected by attorney-client privilege. Prosecutors will be able to use that material to confront any subject or target of the investigation, the judge wrote.

The order was dated Aug. 28, and prosecutors sought to keep it private because they said it identifies people not charged by a grand jury. But on Tuesday, Howell unsealed that document while redacting from view any personally identifiable information.

Pardons are common at the end of a president’s tenure and are occasionally politically fraught affairs as some convicted felons look to leverage connections inside the White House to secure clemency. Last week, President Donald Trump announced that he had pardoned his first national security adviser, Michael Flynn, even as a federal judge was weighing a Justice Department request to dismiss the case.

Spokespeople for the Justice Department did not immediately return an email seeking comment Tuesday evening.

The existence of the investigation was first reported by CNN.