Alexei Navalny, the Russian opposition leader was in intensive care in a Siberian hospital on August 20 after he fell ill in what his spokeswoman said was a suspected poisoning. Navalny, a 44-year-old lawyer and anti-corruption campaigner is among President Vladimir Putin's fiercest critics. He is being treated in a hospital in the city of Omsk after he lost consciousness on a flight to Moscow and his plane made an emergency landing. His spokeswoman Kira Yarmysh wrote on Twitter that Navalny had been placed in a coma on a ventilator and that tests were being carried out. State news agency TASS reported that Navalny was in the intensive care unit for toxicology patients in Omsk Emergency Hospital No. 1. "He is in a serious condition," the hospital's chief doctor Alexander Murakhovsky told TASS.