Navalny's associates said that a bottle of water with a trace of the Novichok nerve agent was found in his hotel room in Tomsk.
Russian doctors claim 'no trace' of poison in Alexei Navalny, refuse to transfer Kremlin critic overseas for treatment
Navalny, one of President Vladimir Putin's fiercest critics, remains in a coma in intensive care after a suspected poisoning his allies link to his political activity and believe was engineered by the Kremlin
The series of YouTube videos featured Navalny inviting Russians to join demonstrations on Sunday.
Russia presidential election: After record win, Vladimir Putin says Moscow will address disputes with the West
Vladimir Putin on Monday said he would address disputes with the West after an election that saw him return to the Kremlin with a record vote share, as Moscow faces increasing isolation
Vladimir Putin cruises to landslide victory in Russian presidential election as Opposition cries foul
Vladimir Putin cruised to victory in Russia's presidential election on Sunday, giving him at least another six years in power
Russian Opposition leader Alexei Navalny freed after brief police detention as thousands protest against upcoming 'pseudo elections'
Russian Opposition leader Alexei Navalny has been freed after a brief spell in police detention in Moscow as thousands rallied against a March election expected to extend Vladimir Putin's Kremlin term
Businessman Alisher Usmanov, whom Navalny targeted in his Medvedev video, also used the Internet to hit back, making two videos of his own questioning Navalny's probity.