MOSCOW—Russian opposition leader Alexei Navalny—widely regarded as a prominent critic of Russian President Vladimir Putin—was admitted to hospital in Siberia on Thursday suffering symptoms of what his spokeswoman called poisoning after his aircraft made an emergency landing.
Navalny, 44, began feeling ill on a plane to Moscow on Thursday morning after drinking tea at an airport cafe in the Siberian city of Tomsk.
His condition became so serious that the plane made an emergency landing at the city of Omsk, en route to Moscow, where he was carried off on a stretcher.
Kira Yarmysh, his spokeswoman, said he was in intensive care in a serious but stable condition, and on an artificial lung ventilator in a hospital in the city, about 2,200 km (1370 miles) east of the Russian capital.
“We assume that Alexei was poisoned with something mixed into his tea. It was the only thing that he drank in the morning. Alexei is now unconscious,” Yarmysh said.
Kremlin spokesman Dmitry Peskov said any poisoning would need to be confirmed by laboratory tests and that doctors were doing everything they could to help Navalny. He wished him a speedy recovery.
Doctors gave contradictory information about Navalny’s condition, saying it had stabilized and that he was in a coma, but also that there was still a threat to his life and they were working to save him.
Navalny’s wife Yulia flew from Moscow to be with him. Yarmysh said hospital officials had so far prevented Navalny’s personal doctor, who had also flown in, from seeing him.
Doctors were also refusing to discharge him so that he could be flown to Europe for emergency treatment, she said. The hospital said his condition meant he could not be moved for now.
Yarmysh drew a parallel with an incident last year in which Navalny suffered an acute allergic reaction one doctor said could have resulted from poisoning with an unknown chemical.
British foreign minister Dominic Raab said he was deeply concerned, as did Lithuanian Foreign Minister Linas Linkevicius.
“If (poisoning is) confirmed, those responsible must face consequences,” Linkevicius said on Twitter.
Navalny, a lawyer and anti-corruption activist, has served several stints in jail in recent years for organising anti-Kremlin protests. He has helped release high-impact investigations into what he has said are outrageous examples of official corruption.
The European Court of Human Rights has ruled that Russia’s arrests and detention of Navalny in 2012 and 2014 were politically motivated and violated his human rights, a ruling Moscow called questionable.
Russia holds regional elections next month and Navalny and his allies have been preparing for them, trying to increase support for candidates which they back.
By Andrew Osborn and Anton Zverev