British founder of Syrian White Helmets found dead in Turkey days after being called a spy

James Le Mesurier was found outside his apartment on Monday

A member of the Syrian Civil Defence known as the "White Helmets", inspects the site of a damaged building reportedly hit during Russian airstrikes on the town of Taftanaz and its surroundings, in SyrShow more

The British founder of a group that helped establish the Syrian White Helmets rescue organisation has died in Istanbul.

James Le Mesurier was discovered with fractures to his legs and head at the foot of his apartment early on Monday.

It comes days after Russia accused him of being a spy.

Mr Le Mesurier was a former British Army officer who founded Mayday Rescue, which helped train the White Helmets when it began in 2013.

The precise details of James Le Mesurier's death could not be confirmed, and his office did not wish to comment further.

Known officially as Syria Civil Defence, the White Helmets are a voluntary search-and-rescue group formed to respond to bombings by Syrian government forces in opposition-controlled parts of Syria.

The White Helmets have become a favourite target of pro-Syrian and pro-Russian groups.

They have accused the group of supporting terrorists in Syria and doctoring footage of atrocities committed by regime forces - claims strongly denied by its supporters.

Just two days ago Russia's foreign ministry tweeted:

"The White Helmets' co-founder, James Le Mesurier, is a former agent of Britain's MI6, who has been spotted all around the world, including in the #Balkans and the #MiddleEast. His connections to terrorist groups were reported back during his mission in #Kosovo."

There are now calls for officials to investigate his death.

Mr Le Mesurier told Al Jazeera in 2015 that he had begun training and supporting the White Helmets in early 2013 alongside Turkish rescue experts, starting with "a single team of 20 people".

"I was working in Istanbul... and got together with a group of Turkish earthquake rescue volunteers," he said.

The White Helmets quickly expanded, and are credited with saving tens of thousands of lives during Syria's conflict.

A documentary about the group won an Academy Award in 2017.