WASHINGTON (AP) — The Justice Department on Tuesday challenged a court order that complicated efforts to seek a new indictment against former FBI Director James Comey by making a trove of evidence off-limits to prosecutors.

Issued over the weekend by U.S. District Judge Colleen Kollar-Kotelly, the order restricts the Justice Department from accessing computer files belonging to Daniel Richman, a close friend of Comey and a law professor at Columbia University. Richman is seen as a pivotal figure in the potential case against Comey.

Prosecutors moved quickly to quash the order, describing Richman’s request for his files as a “strategic tool to obstruct the investigation and potential prosecution.” They argued that the ruling had overstepped judicial authority by mandating the return of Richman’s property, thereby hindering their ability to advance with their case against Comey.

The Justice Department alleges Comey used Richman to relay information to the media about decisions made during the FBI’s investigation of Hillary Clinton’s use of a private email server. Comey was charged in September with lying to Congress regarding whether he had authorized an associate to act as an anonymous source for the media.

Richman’s motion requested the return of his computer and email records, which the Justice Department had initially acquired through search warrants as part of a closed investigation into media leaks. Richman and his lawyers maintain the files contain extensive privileged information.

The Justice Department contested that Richman's motion effectively blocks the government from investigating and pursuing charges against Comey, urging that courts cannot bar federal criminal prosecutions through civil claims.

Judge Kollar-Kotelly has yet to lift her order but has allowed further submissions from both parties, hinting that Richman should have an opportunity to assert any attorney-client privilege claims that might be warranted.