Iskander Makhmudov

The Uzbekistan-born Makhmudov is the main owner of metals conglomerate UGMK, which controls 300 mining companies scattered across Russia.

Makhmudov is also a shareholder in Transmashholding, Russia's largest maker of locomotives and rail equipment.

In 2003, Makhmudov and his former business partner Oleg Deripaska were accused in American courts of leading a "massive racketeering scheme."

They denied it, and the lawsuit was eventually dismissed on jurisdictional grounds.

UGMK spent $100 million building the Shayba ice arena for the 2014 Sochi Olympics, which it gave to the Russian government after the games.