One of Vladimir Putin’s biggest critics is being protected by Germany after an alleged poisoning attack

Germany says it has placed Alexei Navalny under guard in hospital after determining the long-time critic of Russian President Vladimir Putin had most likely been poisoned.

Mr Navalny collapsed on a plane last Thursday after drinking tea that his allies said they believe was laced with poison.

He was flown to Germany for treatment on Saturday.

“The suspicion is that Mr Navalny was poisoned given that unfortunately, recent Russian history has had several such suspected cases,” German Chancellor Angela Merkel’s chief spokesman, Steffen Seibert, said.

“Because one can say with near certainty that it was a poisoning attack, protection is necessary.”

The Russian Government has made no comment on the German statement.

A medical team take a person on a stretcher from a parked aircraft.
A stretcher is taken from special aircraft with the Kremlin critic Alexei Navalny on board at Tegel Airport in Berlin last Saturday.(AP: Michael Kappeler/DPA)

The Kremlin said on Friday it was still unclear what caused Mr Navalny to fall ill and that initial tests did not show he was poisoned.

The incident could further strain Russia’s fraught relations with its European and NATO neighbours, who have accused it of mounting attacks on dissidents in Europe in the past.

Putin and Merkel chat while standing on balcony
German Chancellor Angela Merkel said through her spokeswoman that Russia’s recent history had similar cases to this.(Reuters: Axel Schmidt)

Doctors at the Siberian hospital that first treated Mr Navalny said they had saved his life but that they had not found traces of poison in his system.

“If we had found some kind of poison that was somehow confirmed then it would have been a lot easier for us,” senior doctor Anatoly Kalinichenko said.

“It would have been a clear diagnosis, a clear condition and a well-known course of treatment.”

The Russian doctors did not say what they had treated him for.

Last week, they said they had diagnosed him with metabolic disease possibly brought on by low blood sugar.

The doctors said they had not come under pressure from authorities.

Alexei Navalny
Russian opposition activist Alexei Navalny is in a German hospital, suspected of being poisoned.(AP: Pavel Golovkin)

Kira Yarmysh, Mr Navalny’s spokeswoman, said supporters had reported what they described as a suspected poisoning to the Russian police and Investigative Committee as soon as he fell ill.

Mr Navalny has been a thorn in the Kremlin’s side for more than a decade, exposing what he says is high-level graft and mobilising crowds of young protesters.

He has been repeatedly detained for organising public meetings and rallies and sued over his investigations into corruption.

He was barred from running in a presidential election in 2018.