A federal appeals court on Wednesday unsealed a recent opinion involving the ongoing investigation into D.C. Mayor Vincent C. Gray’s 2010 campaign.

The March ruling by the U.S. Court of Appeals for the District of Columbia Circuit gave federal prosecutors the go-ahead to review millions of pages of records seized from the home and offices of D.C. businessman Jeffrey E. Thompson.

Wednesday’s decisions gives the public its first glimpse at the reasoning behind that opinion.

Thompson, who is the subject of a grand jury investigation, is alleged to have financed a “shadow campaign” for Gray that was not disclosed as required by election laws.

A three-judge panel of the court essentially decided not to get involved in the middle of an investigation, dismissing Thompson’s appeal of a lower court ruling for lack of jurisdiction. Thompson had argued that some of the documents seized on March 2 went beyond the scope of the search warrants.

The 16-page opinion notes that the government has already made available to Thompson most of the property seized and that Thompson is concerned less about the return of his property than about the “unlawful revelation of …private information.”

Thompson “seeks to prevent the government from reviewing all or most of the evidence for a period of time, while [Thompson] and an independent third party screen the seized material,” the opinion states.

The ruling also offers insight into the status of the investigation. In January, according to the opinion, the U.S. Attorney’s Office reached an agreement with Thompson about how to weed out other documents protected by various privileges.

But the status of at least some of the records is still in limbo. Thompson has until the end of July to decide whether to seek review by the Supreme Court.

The unsealed ruling redacts specific references to Thompson, but it is clear from lower court opinions that he is the subject of the case.

The court agreed to unseal its ruling in response to a request from the Reporters Committee for Freedom of the Press. The nonprofit group that provides free legal assistance to journalists, including The Washington Post, questioned the need for complete secrecy when a redacted version of the lower court opinion had already been reported by news organizations.