Len Blavatnik donated $3.5 million to Mitch McConnell's PAC from 2015 to 2017.

Ukrainian-born billionaire Len Blavatnik, who holds dual U.S.-U.K. citizenship, used to be a fairly run-of-the-mill campaign contributor, donating relatively modest amounts in a bipartisan fashion — and then the 2016 election cycle hit.

Beginning in 2015, Blavatnik lavished contributions on Republicans, with Senate Majority Leader Mitch McConnell alone on the receiving end of $3.5 million between 2015 and 2017.

Via Dallas News:

Blavatnik contributed a total of $3.5 million to a PAC associated with Senate Majority Leader Mitch McConnell, R-Ky. Blavatnik contributed $1.5 million to the GOP Senate Leadership Fund PAC in the name of Access Industries and another $1 million in the name of AI-Altep Holdings during the 2015/2016 election season. And as of September 2017, he had contributed another $1 million this year through AI–Altep.

Blavatnik, whose family emigrated to the U.S. in the late 1970s, is a longtime business associate of Russian oligarchs Oleg Deripaska and Viktor Vekselberg, both of whom have ties to Russian President Vladimir Putin.

Along with McConnell, Republican Senators Marco Rubio and Lindsey Graham received hefty sums from Blavatnik as well.

Read the full report here.