Putin critic Alexei Navalny 'probably poisoned' - doctors

The Berlin hospital treating the seriously ill Russian opposition leader, Alexei Navalny, says he appears to have been poisoned, the BBC reports.

The Charite hospital released a statement saying "clinical evidence suggests an intoxication through a substance belonging to the group of cholinesterase inhibitors".

His condition was "serious but not life-threatening" the statement said.

He fell ill on an internal flight in Russia on Thursday.

Video appeared to show Mr Navalny, a dogged critic of the Kremlin, writhing in agony on the flight from Tomsk in Siberia to Moscow.

His supporters suspect poison was placed in a cup of tea he drank at the airport in Tomsk.