“The plane made an urgent landing in Omsk.
“Alexei has toxic poisoning. ”
READ MORE: Poisoning Russia: Putin’s rival rushed to hospital
She added, “We suspect Alexei was poisoned by something mixed in tea. It was the only thing he had drunk since the morning.
“Doctors say that the toxic agent is absorbed faster through the hot liquid. Currently, Alexei is unconscious. ”
A passenger on the plane Pavel Lebedev said: “At the start of the flight, he went to the toilet and did not come back.
“He started to feel really sick.
Other disturbing footage shows Mr Navalny was taken to hospital on a stretcher after the plane was forced to make an emergency landing.
Putin’s political opponent drank tea in a cafe at Tomsk airport before boarding his flight.
It was said that the drink was the only thing he had consumed that day.
Cafe owners would check CCTV cameras to try to establish what had happened, the Interfax news agency reported.