White Helmets backer dies 'in fall from balcony of his home'
Mystery surrounds the death of a former British soldier who backed Syria's White Helmets rescue group after his body was found in the street days after the Kremlin accused him of being an MI6 agent with terrorist connections.
James Le Mesurier (48) is thought to have fallen from a balcony at his Istanbul home.
British intelligence agencies are monitoring the situation with Whitehall sources stressing it was too soon to say if he was a victim of foul play.
The intelligence services have questioned persistent Russian attacks against Mr Le Mesurier for his support and training of the rescue group.
One Syrian expert said he had faced "unimaginable pressure and targeting as a result".
Turkish security officials suggested it was being treated as a suspected suicide.