Former Acting Attorney General Sally Yates testified Monday that she first warned the White House days after inauguration that then-national security adviser Michael Flynn had misled members of the Trump administration about his contacts with Russian officials, and that Russia knew about those conversations.

“We felt like it was critical that we get this information to the White House because, in part, the Vice President was unknowingly making false statements to the public, and because we believed that Gen. Flynn was compromised with respect to the Russians,” Yates said in a highly-anticipated hearing held by the Senate Judiciary Committee’s subcommittee on crime and terrorism.

Yates said she and a member of the Justice Department’s national security division met with White House Counsel Don McGahn in his office on Jan. 26 to let him know that Vice President Mike Pence and other administration officials were going on the record with comments about Flynn’s contacts with Russia “that we knew to be untrue.”

She declined to describe how DOJ learned that what Flynn was telling others in the administration was in fact untrue, saying that information was classified.

“We took him through a fair amount of detail about the underlying conduct what Gen. Flynn had done and then we walked through the various press accounts and how it had been falsely reported,” Yates said, calling Flynn’s “underlying conduct,” which she said was also classified, “problematic in and of itself.”

Yates said she also informed McGahn that the FBI interviewed Flynn at the White House on Jan. 24, and declined to answer McGahn’s question about how he “did.”

“We were concerned that the American people had been misled about the underlying conduct and what Gen. Flynn had done and additionally that we weren’t the only ones that knew all of this, that the Russians also knew about what Gen. Flynn had done,” Yates testified.

“The Russians also knew that Gen. Flynn had misled the Vice President and others, because in the media accounts it was clear that they were repeating what Gen. Flynn had told them. And that this was a problem because not only did we believe that the Russians knew this but that they likely had proof of this information,” she continued. “And that created a compromise situation, a situation where the national security advisor essentially could be blackmailed by the Russians.”

Yates testified that McGahn called her and the unnamed DOJ official into his White House office again on Jan. 27, where she said McGahn asked her if she thought Flynn should be fired.

The acting attorney general said she told McGahn it was not her position to say so, but that she brought the information to him so that the Trump administration could “take action.”

McGahn asked for access to the underlying evidence supporting their claims, according to Yates, who told him she’d would work with the FBI to determine what could be revealed over that weekend.

On Jan. 30, a Monday, Yates said she called McGahn granting him approval to review that underlying evidence. She was dismissed from her post hours later, after instructing the Justice Department not to defend President Donald Trump’s travel ban out of concern over its legality.

Flynn remained in his position until Feb. 13.

This post has been updated.