In a new report Thursday, BuzzFeed reporters found a previously undisclosed vector in Russia's sprawling effort to interfere in American affairs in 2016, including most prominently the presidential election, which raises serious questions about the possible involvement of employees of the federal government. According to the reporting, Treasury officials were in communications with Russian agents over an unsecured email backchannel while the Russians made troubling requests.

The report explained:

The extraordinary unofficial line of communication arose in the final year of the Obama administration — in the midst of what multiple US intelligence agencies have said was a secret campaign by the Kremlin to interfere in the US election. Russian agents ostensibly trying to track ISIS instead pressed their American counterparts for private financial documents on at least two dozen dissidents, academics, private investigators, and American citizens. Most startlingly, Russia requested sensitive documents on Dirk, Edward, and Daniel Ziff, billionaire investors who had run afoul of the Kremlin. That request was made weeks before a Russian lawyer showed up at Trump Tower offering top campaign aides “dirt” on Hillary Clinton — including her supposed connection to the Ziff brothers.

Officials even reportedly told their superiors about the unsecured communications but continued to use the backchannel anyway as late as 2017. Federal employees had been warned that Russia could be seeking "sensitive financial records — including Social Security and bank account numbers — to spy on, endanger, or recruit targets in the West."

The Treasury Department told BuzzFeed that it does not comment on its communications with foreign officials, but it has passed along the allegations to internal investigators.

One source told BuzzFeed that the vulnerability caused by the backchannel could have corrupted internal servers.