Pictured: Vladimir Putin’s arch-foe Alexei Navalny minutes before collapsing in suspected poisoning

A woman who took this selfie with Russian opposition leader Alexei Navalny told on Saturday night of how the arch-critic of President Putin collapsed in agony just minutes later.

The opposition leader posed with the female supporter moments before taking his seat on a flight from the Siberian city of Tomsk to Moscow on Thursday.

The woman described how 40 minutes into the flight, Mr Navalny got up and went to the toilet, where he started ‘screaming like a beluga whale’.

She added: ‘There were two young people with Alexei, a young man and a young woman, and they were screaming, “Don’t shut your eyes Lesha [Navalny’s nickname], breathe, breathe!”

‘He didn’t sound like a human being the way he yelled.’

After an emergency landing at Omsk airport, about 500 miles south of Tomsk, Mr Navalny was taken to a local hospital and put into an induced coma.

Doctors in Siberia claimed the 44-year-old had been left fighting for his life due to ‘low blood sugar’ but his allies rejected this and called on international help to uncover the truth.

Mr Navalny was flown to Germany yesterday after his wife Yulia wrote a letter to Mr Putin demanding that he allow her husband to be flown to Berlin for treatment. 

He was escorted to Charite Hospital under heavy police protection and medics last night described his condition as ‘serious’.

Mr Navalny drank a cup of tea at a cafe inside Tomsk airport, which his supporters suspect had been poisoned because it was all he ate or drank that morning. Mr Navalny was flown to Berlin on a Challenger 604 air ambulance arranged by the Cinema for Peace Foundation. 

Its founder, Jaka Bizilj, a friend of Mr Navalny, said: ‘His health condition is very worrying.

‘We got a very clear message from the doctors that had there not been an emergency landing at Omsk, he would have died.’ 

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. 

The Russian government denies claims of poisoning. However, Mr Navalny has been repeatedly detained for organising public meetings and rallies and sued over his investigations into corruption. He was barred from running in the 2018 Russian presidential election.

In 2017, he was attacked by several men who threw antiseptic solution in his face, damaging an eye, and last year he was rushed to a hospital from jail where he was serving a sentence on charges of violating protest regulations.

His team also suspected poisoning then.

The Mail on Sunday has investigated questions over the authenticity of a published photograph of Mr Navalny sipping a cup of tea at Tomsk airport that is suspected of containing poison.

Our reporter yesterday visited the Vienna Coffeehouse counter at Tomsk airport where the Mr Navalny was pictured by Pavel Lebedev, a Russian DJ and blogger. 

Comparisons of that photo and the scene yesterday show the backgrounds are identical. The cafe is closed and the area where Mr Navalny sat was cordoned off with tape, but not guarded.

A saleswoman at a nearby souvenir shop said: ‘Police closed the cafe and all the waitresses were interrogated. They were just sobbing here, poor girls.’

The saleswoman, who did not want to be identified, said one of Mr Navalny’s entourage bought the tea at the counter and took it to him at the table.