Russian police have opened a criminal investigation into the poisoning death in London of former KGB agent Alexander Litvinenko.
Prosecutors in Moscow say they are also expanding their probe to include what they say may be an attempt to kill Russian businessman Dmitri Kovtun. They say Kovtun met Litvinenko on the same day that the former Russian spy became seriously ill.
Russian media Thursday reported that Kovtun was in critical condition, reports denied by his lawyer, who described his health as satisfactory.
British authorities say seven staff members at a London hotel Litvinenko visited on November 1, the day he became ill, have tested positive for low levels of radiation poisoning.
Litvinenko died three weeks ago from what British authorities say was a lethal dose of the radioactive substance polonium-210. He was buried in London on Thursday.
In a deathbed statement, the former spy accused Russian President Vladimir Putin of ordering his murder. Kremlin officials deny any involvement in Litvinenko's death.