Russia yet to establish official cause of Navalny death

MOSCOW, Feb 19 (Reuters): Russian investigators have not yet established the cause of Alexei Navalny's death and it is unclear how long it will take for official conclusions to be made, his mother was told, Navalny's spokeswoman said on Monday.

Navalny, a 47-year-old former lawyer, fell unconscious and died on Friday after a walk at the "Polar Wolf" penal colony in Kharp, about 1,900 km (1,200 miles) northeast of Moscow, where he was serving a three-decade sentence, the prison service said.

Navalny's mother, Lyudmila, was told on Saturday at the prison colony that he had perished from "sudden death syndrome", a vague term for different heart conditions that end in death, according to Navalny's team.