The Russian Prosecutor General's Office said Leonid Nevzlin, a core shareholder of the bankrupt oil company, who lives in Israel and is on the international wanted list on fraud charges, could have ordered Litvinenko's poisoning with polonium-210.
"We are checking a version that people, who are on the international wanted list for grave crimes, including [former] Yukos co-chairman Leonid Nevzlin, could be behind these crimes," the office said, referring to Litvinenko's murder and an attempt on his business partner Dmitry Kovtun's life.
Litvinenko reportedly investigated Moscow's handling of the Yukos affair before he died in London November 23.
Nevzlin's lawyer said the statement is a new provocation against his client and an attempt to pin as many crimes as possible on him.
"The Prosecutor General's Office finds it easier to pin all crimes on those [Russians] who live abroad," Dmitry Kharitonov said.
Nevzlin, who has Israeli citizenship, has also been charged in Russia with involvement in a number of contract killings, and was put on the international wanted list in July 2004. The businessman denies the charges, and Israel has refused to extradite him to Russia.
Prosecutors said they will soon resume attempts to have those people extradited.
The U.K. is home to more than a dozen suspects wanted in Russia in connection with the Yukos case. The country also harbors Akhmed Zakayev, a Chechen separatist leader wanted in Russia on terrorism charges, and controversial tycoon Boris Berezovsky.
London has refused repeated Russian requests for their extradition.