Russian opposition politician Alexei Navalny was in a coma in a Siberian hospital on Thursday after drinking a cup of tea that his spokeswoman said she believed was laced with poison.
Navalny, 44, was in intensive care and on an artificial lung ventilator, spokeswoman Kira Yarmysh said on social media.
A fierce critic of President Vladimir Putin, Navalny started feeling ill when returning to Moscow from Tomsk in Siberia by plane on Wednesday morning, Yarmysh said.
“We assume that Alexei was poisoned with something mixed into his tea. It was the only thing that he drank in the morning. Doctors say the toxin was absorbed faster through the hot liquid. Alexei is now unconscious,” Yarmysh said.
She did not say who she believed may have poisoned Navalny, but said police had been called to the hospital.
However, one of the doctors there said it was not certain that he had been poisoned. Doctor Anatoly Kalinichenko said “natural poisoning” was one of several diagnoses being considered and tests were being carried out.
Navalny, a lawyer and anti-corruption activist, has served many stints in jail in recent years for organising anti-Kremlin protests and has been physically attacked in the street by pro-government activists.
He has helped investigations into what he has said are outrageous examples of official corruption.