OK, this is a wild one. A key Russian from the Yeltsin-Berezovsky era who, like Berezovsky, could be considered an oligarch seems to be implicating Berezovsky in the Politkovskaya and Litvinenko deaths, and the sudden Gaida illness:

Anatoly Chubais, a top Yeltsin-era government official and now head of the national electricity monopoly, said he suspects there is a link between Gaidar’s illness, Litvinenko’s death and last month’s murder of investigative reporter Anna Politkovskaya.

“The theory of attempted poisoning, attempted murder should undoubtedly be considered seriously,” Chubais told state-run Rossiya television.

“The chain of deaths of…Politkovskaya, Litvinenko and Gaidar would perfectly correspond to the interests and the vision of those people who are openly talking about a forceful, unconstitutional change of power in Russia as a possible option.”

Chubais didn’t name anyone but his statement sounded like an allusion to Boris Berezovsky, a self-exiled Russian tycoon and arch-foe of the Kremlin who has talked about a possible forceful change of government in Russia. Berezovsky, who was given asylum in Britain, had close contacts with Litvinenko.

Russian legislators and politicians have suggested Berezovsky could have been behind the deaths of Politkovskaya and Litvinenko as part of a plan to blacken the reputation of President Vladimir Putin and the Kremlin.

Along with Chubais, Gaidar is best known for as the architect of the sweeping free-market measures that were instituted in the early years of Yeltsin’s administration. He is one of the leaders of the liberal opposition party Union of Right Forces and heads a think-tank called the Institute for the Economy in Transition.

Seems we have more theories than we know what to do with on this mystery.