Disturbing audio was released Thursday of a quietly insistent voicemail from Donald Trump’s former personal attorney demanding a “heads up” about what Michael Flynn’s was telling Robert Mueller investigators that might “implicate” the president.

John Dowd’s call to Flynn’s attorney Robert Kelner also appeared to hint at a pardon for the former national security adviser if he stopped cooperating with the special counsel’s investigation into Russian interference in the 2016 campaign.

Though the content of the call was previously known, the new audio of Dowd’s voicemail packs an ominous punch. His tone is quiet and friendly but insistent.

Dowd underscored in the call that any detail that “implicates the president” could be a “national security” issue. He encouraged any such information to be shared with him for the sake of the country, for Trump — and “for the sake of all of our interests.”

He refers in the call to the president’s “feeling” about Flynn, which “still remains.” The comment has been widely interpreted as a message of loyalty from Trump, hinting at the possibility of a pardon if Flynn kept his mouth shut. Dowd has denied that.

Flynn pleaded guilty in late 2017 to lying to the FBI about his contacts with Russians just days after Trump took office. He resigned as Trump’s national security adviser early that year. He’s still awaiting sentencing.

But in a legal-team shakeup Thursday, Flynn dismissed the lawyers who represented him in his guilty plea and cooperation with Mueller and retained new counsel. It wasn’t immediately clear how the change would affect his case. He is still cooperating with investigators in cases against his former business partner.

Much of the transcript of Dowd’s voicemail was first released in the redacted Mueller report as one of 10 instances of possible obstruction of justice by Trump using his authority to thwart the Mueller probe. The full voicemail transcript was released last week.

The audio was released under orders from the judge in Flynn’s case. When it was aired by Jake Tapper on Thursday (listen in the video above), CNN White House reporter Jeremy Diamond said he was startled by Dowd’s apparent expectation that Trump could be implicated in a crime by Flynn.

Here’s a transcript of the call, which refers to at least one other previous phone call from Dowd.

Hey, Rob, uhm, this is John again. Uh, maybe I-I-I’m sympathetic. I understand your situation. But let me see if I can’t state it in starker terms. If you have — and it wouldn’t surprise me if you’ve gone on to make a deal with, and, uh, work with the government — I understand that you can’t join the joint defense, so that’s one thing. If, on the other hand, we have, there’s information that implicates the president, then we’ve got a national security issue, or maybe a national security issue, I don’t know, some issue, we’ve got to deal with, not only for the president, but for the country. So, uh, you know then, you know we need some kind of heads up. Um, just for the sake of protecting all our interests, if we can, without you having to give up any confidential information. So and if it’s the former, then, you know, remember what we’ve always said about the president and his feeling toward Flynn, and that still remains. Well, in any event, let me know, and I appreciate your listening and taking the time. Thanks, pal.

Dowd attacked the Mueller report’s characterization of his voicemail as an attempt to stop or influence Flynn’s cooperation with the investigation as “baseless” and a “smear.”