Alexei Navalny was likely poisoned, according to German doctors. Russian doctors previously said that Navalny, a prominent opponent of Putin, did not have traces of poison in his system. "The patient is in an intensive care unit and is still in an induced coma. His health is serious but there is currently no acute danger to his life," the German hospital where Navalny is being treated said. Russian authorities initially would not allow Navalny to be leave the country, but he was taken to Germany for further treatment late last week. Visit Business Insider's homepage for more stories.
German doctors have concluded that Kremlin critic Alexei Navalny was likely poisoned after conducting tests, the Associated Press reported. Navalny's team suspected he was poisoned, and this marks the first corroboration from medical experts after Russian doctors previously said no traces of poison were detected. Russian President Vladimir Putin's critics and opponents have frequently been poisoned or harmed, sometimes fatally, in other ways. The Charité hospital where Navalny is being treated said "cholinesterase inhibitors" were found in his system. Cholinesterase inhibitors are substances found in a number of drugs in addition to pesticides and nerve agents. It's unclear what specific substance Navalny may have been exposed to. "The patient is in an intensive care unit and is still in an induced coma. His health is serious but there is currently no acute danger to his life," the hospital said in a statement, per the Associated Press. Navalny fell ill on a flight back to Moscow from the Siberian city of Tomsk last week. His team said Navalny had only consumed tea prior to the flight, which is how they suspect he was poisoned. Initially, authorities would not permit Navalny to leave Russia, but he was eventually transferred to Germany late last week. Navalny's team accused Russian officials of blocking Navalny from leaving so that any traces of poison would disappear from his system. The anti-corruption campaigner is considered Putin's most prominent opponent. He has faced attacks in the past and frequently been harrassed by law enforcement. Navalny campaigned to challenge Putin in 2018 but was formally barred from running for president. Though President Donald Trump has barely acknowledged the suspected poisoning of Navalny, the matter is on Deputy Secretary of State Stephen Biegun's agenda for a trip to Russia that begins Tuesday, US Ambassador to Russia John Sullivan told reporters. Join the conversation about this story » NOW WATCH: Why you don't see brilliantly blue fireworks