The Justice Department refused on Friday to cooperate with a judge’s demand that it publicly release transcripts of recorded conversations between Michael Flynn and Russia’s ambassador to the United States in December 2016.

The refusal was a response to U.S. District Judge Emmet G. Sullivan, who ordered earlier this month that the Justice Department release several materials related to the case against Flynn, who was President Donald Trump’s campaign adviser and his national security adviser until being ousted for lying about his contacts with the Russians.

In their refusal, the federal prosecutors said they hadn’t used those recordings of Flynn’s conversations to establish his guilt or recommend a sentencing.

“The government further represents that it is not relying on any other recordings, of any person, for purposes of establishing the defendant’s guilt or determining his sentence, nor are there other recordings that are part of the sentencing record,” the court filing’s lone statement on the request read.

One of the Washington Post journalists who first reported the story, Carol Leonnig, tweeted that it may be unprecedented for the government to refuse a court order in such a way.