A hospital in Germany has contradicted Russian doctors who claimed there was no sign opposition leader Alexei Navalny was poisoned. Berlin's Charité hospital, which began treating the 44-year-old on Saturday, says there are signs he was poisoned, the BBC reports. In a statement, the hospital said that while the exact substance involved has not been determined, "clinical evidence suggests an intoxication through a substance belonging to the group of cholinesterase inhibitors." NPR describes those inhibitors as ones that interfere with the body's ability to break down a key neurotransmitter. Navalny, who is still in a medically induced coma, is being treated with an antidote for cholinesterase inhibitors.
After Navalny became seriously ill on a flight Thursday, aides said they believed his tea had been poisoned; doctors who treated Navalny before he was flown to Germany claimed he suffered a "metabolic collapse," possibly from low blood sugar. Biological counter-terrorism expert Hamish de Bretton-Gordon tells the Guardian that the tests suggest Navalny was poisoned with a nerve agent and calls his cholinesterase levels an important "jigsaw piece in the puzzle." Navalny "was attacked with some sort of chemical, in the same way as Alexander Litvinenko, Sergei Skripal, and a host of others," he says. Doctors in Germany say Navalny is expected to survive, CNN reports. "His state of health is serious, but there is currently no acute danger to his life," their statement said. (Germany says Navalny is being protected by police.)