In August 2020, a plane travelling from Siberia to Moscow made an emergency landing. One of its passengers, Russian opposition leader Alexei Navalny, was deathly ill. Taken to a local Siberian hospital and eventually evacuated to Berlin, doctors there confirmed that he had been poisoned with Novichok, a nerve agent implicated in attacks on other opponents of the Russian government. President Vladimir Putin immediately cast doubt on the findings and denied any involvement.