(CNN) Hillary Clinton personally approved her campaign's plans in fall 2016 to share information with a reporter about an uncorroborated alleged server backchannel between Donald Trump and a top Russian bank, her former campaign manager testified Friday in federal court.
Robby Mook said he attended a meeting with other senior campaign officials where they learned about strange cyberactivity that suggested a relationship between the Trump Organization and Alfa Bank, which is based in Moscow. The group decided to share the information with a reporter, and Mook subsequently ran that decision by Clinton herself.
"We discussed it with Hillary," Mook said, later adding that "she agreed with the decision."
A campaign staffer later passed the information to a reporter from Slate magazine, which the campaign hoped the reporter would "vet it out, and write what they believe is true," Mook said.
Slate published a story on October 31, 2016, raising questions about the odd Trump-Alfa cyber links. After that story came out, Clinton tweeted about it, and posted a news release that said, "This secret hotline may be the key to unlocking the mystery of Trump's ties to Russia."
The testimony came in the criminal trial of Clinton campaign lawyer Michael Sussmann, who is being prosecuted by the Trump-era special counsel John Durham. Durham is investigating potential misconduct tied to the FBI's Trump-Russia probe. The trial has shed light on the dark arts of political opposition research -- and how campaigns dig up dirt and plant stories in the press.
Federal investigators ultimately concluded there weren't any improper Trump-Alfa cyber links.
Sussmann passed along the same information about Trump and Alfa Bank to an FBI official in September 2016. Prosecutors charged him with lying to the FBI and allege that he falsely told the FBI official that he wasn't there for a client, even though he was there on Clinton's behalf.
He has pleaded not guilty and maintains that he went "to help the FBI" as a concerned citizen, and that the Clinton campaign wouldn't have wanted him to meet with the FBI in the first place.
Mook and another top Clinton campaign official, general counsel Marc Elias, reinforced that assertion this week on the witness stand. They both testified they didn't authorize or direct Sussmann to go to the FBI with the explosive Trump tip. Mook said Friday that he didn't even know who Sussmann was during the 2016 campaign, and would've opposed an FBI meeting.
"Going to the FBI does not seem like an effective way to get information out to the public," Mook said. "You do that through the media, which is why the information was shared with the media."
Earlier in the week, Elias told the jury that he didn't authorize Sussmann's meeting with the FBI, which occurred on September 19, 2016. Elias said he hadn't learned about the fateful meeting between Sussmann and then-FBI General Counsel James Baker until Sussmann was indicted.
In addition to going to the FBI, Sussmann provided the technical internet data to a reporter from The New York Times, who was working on a story that the FBI spiked after learning about it from Sussmann. A staffer from Fusion GPS, an opposition research firm hired by the Clinton campaign, testified that she met with a Slate reporter to discuss the Trump-Alfa allegations.
Testimony from witnesses suggested the media outreach wasn't closely coordinated, though the situation isn't fully clear. Mook said he didn't know about Perkins Coie, the law firm where Sussmann and Elias worked, "playing a role with us sharing the information with the media."
Inside the courtroom, prosecutors showed the jury Clinton's tweet about the Trump-Alfa article from Slate, and Mook read aloud portions of the campaign's news release about the story. The release was from Jake Sullivan, who is currently President Joe Biden's national security adviser.
"We can only assume that federal authorities will now explore this direct connection between Trump and Russia as part of their existing probe into Russia's meddling in our elections," Sullivan said in the release on October 31, 2016, one week before Election Day.
The special counsel team has previously said that the Clinton campaign's media blitz around the Slate story "is the very culmination of Mr. Sussmann's work and strategy," to allegedly gin up news coverage about the Trump-Alfa allegations and then get the FBI to start an investigation.
During the hearing, Twitter users recirculated Clinton's old post. It caught the eye of billionaire Elon Musk, who has become increasingly vocal about political matters while he tries to buy Twitter, and recently announced his support for the Republican Party. He called the Trump-Alfa allegation "a Clinton campaign hoax" and claimed that Sussmann "created an elaborate hoax."
Sussmann's lawyers declined to comment to CNN about Musk's tweets.
There is no evidence to support Musk's claim that Sussmann or the Clinton campaign peddled information they knew was untrue. Multiple witnesses testified that respected cyber experts harbored genuine national security concerns about the data. Sussmann's lawyers repeatedly said he had no reason to doubt the accuracy of the material when he provided it to the FBI.
This story has been updated with additional details Friday.