Russian police announced on Thursday that they have launched a preliminary examination into opposition leader Alexei Navalny's illness, after the Kremlin rejected German doctors' findings that he was likely poisoned.
Transport police in Siberia said they have started a "pre-investigation check" into what led to Navalny's hospitalization in the city of Omsk, to establish "all the circumstances" and decide whether or not to open a criminal investigation.
Navalny, 44, is in a medically induced coma in a Berlin hospital, where he was airlifted to on Saturday after collapsing during a flight.
The German clinic treating him said its initial examination pointed to poisoning. Doctors at Berlin's Charite hospital said they suspected that Navalny could have been poisoned with a nerve agent, resembling the poisoning of former Russian double agent Sergei Skripal in Salisbury, England, two years ago.
Doctors said he was likely poisoned with a substance in the cholinesterase inhibitors group of chemicals, a type of substance often found in pesticides and nerve agents.
However, the doctors at the Russian hospital where he was initially treated have disagreed with that diagnosis.
German government spokesman Steffen Seibert said on Monday that it was likely Navalny was poisoned. "The suspicion is... that somebody poisoned Mr. Navalny," Seibert said.
Chancellor Angela Merkel also called on Russian President Vladimir Putin to "fully investigate this act as a matter of urgency."
While Navalny's condition is serious, doctors say that there "is currently no acute danger to his life."
Doubts, however, remain about the Kremlin critic's health in the future. "The outcome of the disease remains uncertain and after effects, especially in the area of the nervous system, cannot be excluded at this time," a hospital statement issued on Monday said.
Read more: Was Alexei Navalny poisoned with Novichok?
The activist is one of Putin's most vocal domestic critics and has organized several protests against the Russian leader, whom he accuses of supporting widespread corruption.
lc/stb (AFP, Reuters)