Moscow: Russian opposition figure Alexei Navalny is unconscious in hospital suffering from suspected poisoning, his spokeswoman has said.
The anti-corruption campaigner fell ill during a flight and the plane made an emergency landing in Omsk, spokeswoman said, adding that they suspected something had been mixed into his tea.
The Kremlin said that it wished Navalny a 'speedy recovery'.
Navalny, 44, has been a staunch critic of President Vladimir Putin.
In June, he described a vote on constitutional reforms as a "coup" and a "violation of the constitution". The reforms allow Putin to serve another two terms in office.