EPIC appeared to be seeking similar records Mueller might have prepared with an eye to sending them to Congress. After getting no response to the request, the privacy-focused group filed suit last March.

According to the court filing Friday, the Justice Department's initial search turned up no records about actual or potential reports to Congress, but the agency agreed to perform another search after EPIC refined their request. That search also came up dry, Justice lawyers told EPIC on Thursday, the filing says.

While the Mueller lawyers may not have prepared any reports explicitly labeled as referrals or potential referrals to Congress, the final report the special counsel's team drafted last spring was prepared in anticipation that substantial portions of it would be released to the public, which includes Congress.

Some observers compared that report as impeachment fodder akin to the Watergate "road map," although the articles of impeachment the House approved last December largely overlooked the conduct in the Mueller report, including acts analyzed by Mueller's prosecutors as potential obstruction of justice by President Donald Trump.

The House Judiciary Committee is still battling for access to grand jury secrets in the Mueller report. Last October, a judge rejected the Trump administration's arguments that such information should remain off limits to lawmakers. The Justice Department's appeal of that decision is pending at the D.C. Circuit Court of Appeals.

DOJ did report finding records, including the Mueller report itself, that were responsive to other parts of EPIC's request. The suit will continue as the group challenges privacy-based redactions to the version of the report Justice made public last year.