A senior aide to Russian President Vladimir Putin has claimed the murders of journalist Anna Politkovskaya and former spy Alexander Litvinenko are part of an attack by powerful groups against the head of state.
Mr Litvinenko's death in London on November 23rd from polonium poisoning followed the murder in Moscow of Ms Politkovskaya; both were critics of Mr Putin.
"Polonium-Litvinenko-Politkovskaya are all linked together," Igor Shuvalov was quoted as saying today. "There are strong groups which have joined together to constantly attack the president's line and him personally. . . . None of these murders are in our interests."
The Kremlin has said Mr Litvinenko's lucid deathbed statement accusing Mr Putin of his death was nonsense.
But the murders scuffed Mr Putin's image abroad and strained Moscow's relations with the European Union and the United States.
Some pro-Kremlin politicians have suggested Mr Putin's opponents abroad might be seeking to use the murders to muddy the Kremlin's image. Mr Shuvalov did not name the people who could be seeking to undermine Mr Putin.
The president's opponents include tycoon Boris Berezovsky, who lives in London, and Leonid Nevzlin, a former top manager of the Yukos business empire, who lives in Israel.
Both fled Russia after what they called Kremlin-backed persecution. Russian prosecutors have said they want to question Mr Berezovsky in the Litvinenko case.