Former acting Attorney General Sally Yates told the Senate Monday that she told the Trump administration about former national security adviser Mike Flynn's contacts with Russian officials because she worried Flynn could be blackmailed.

Yates determined that Flynn was not telling the truth when he said he didn't discuss Russian sanctions when he met with the Russian ambassador. Yates told a Senate Judiciary subcommittee that there was a fear that Russia knew that was false, and could try to compromise Flynn.

"[T]his was a problem, because not only did we believe that the Russians knew this, but that they likely had proof of this information," she said. "And that created a compromise situation, a situation where the national security adviser essentially could be blackmailed by the Russians."