The FBI cautioned four years ago that a foundation controlled by Russian oligarch Viktor Vekselberg might be a conduit for Russian espionage, NPR reports.

In 2014, FBI Assistant Special Agent in Charge Lucia Ziobro wrote in the Boston Business Journal that Vekselberg, one of the richest men in Russia and a member of President Vladimir Putin’s inner circle, could have been a part of a spying campaign with interests in American technology.

"The foundation may be a means for the Russian government to access our nation's sensitive or classified research, development facilities and dual-use technologies with military and commercial applications," Ziobro wrote at the time. "This analysis is supported by reports coming out of Russia itself."

ADVERTISEMENT

Vekselberg’s name has resurfaced in the news due to a $500,000 payment a subsidiary company he owns made to Michael Cohen, President Trump Donald John TrumpOmar fires back at Trump over rally remarks: 'This is my country' Pelosi: Trump hurrying to fill SCOTUS seat so he can repeal ObamaCare Trump mocks Biden appearance, mask use ahead of first debate MORE's personal lawyer.

Michael Avenatti, the attorney for Stormy Daniels who first revealed the payment, questioned whether Cohen used the money to pay Daniels in the months leading up to the 2016 presidential election. Daniels says she had an affair with Trump in 2006.

Though a U.S. subsidiary of Vekselberg’s company has acknowledged making payments to Cohen, it has denied serving as a channel for the Russian oligarch or anyone else attempting to transfer funds to him.

Federal agents reportedly stopped Vekselberg at a New York-area airport earlier this year to question him. The interest in Russian businessmen appears to suggest that the special counsel is intensifying its focus on possible connections between Russian oligarchs and Trump's campaign.