The founder of an organization that launched the Syrian White Helmets has been found dead near his home in Istanbul.

James Le Mesurier's body was found on Monday in the central Beyoglu district of the city.

Turkish authorities have yet to confirm how he died, but state-run Anadolu news agency is reporting that he may have fallen to his death. The Istanbul governor's office said "comprehensive administrative and judicial investigations" into Le Mesurier's death had been initiated.

The White Helmets confirmed his death on the organization's Facebook page and tweeted its condolences to his family.

Read more: Turkey: Babies behind bars

His death follows just days after the Russian Foreign Ministry, in a series of tweets on November 8, wrote that Le Mesurier had "connections to terrorist groups." Moscow said that the Syrian Civil Defense, the formal name of the White Helmets, assisted the "most dangerous terrorist groups" in Syria.

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Who was James Le Mesurier?

James Le Mesurier's Mayday Rescue launched the Syrian White Helmets, a volunteer rescue group credited with saving thousands of lives in the Syrian civil war

James Le Mesurier was a former British army officer. He was founder of the not-for-profit Mayday Rescue group, which, according to its website, "builds emergency response capacity in communities at risk of conflict and natural disaster."

The group began operations in 2014, and opened its Istanbul office in 2015 to support its most prominent rescue project, the Syrian White Helmets.

Le Mesurier has received personal awards in the UK for his work with the White Helmets, a former failed nominee for the Nobel Peace Prize and winner of the Alternative Nobel Peace Prize.

Besides its project in Syria, Mayday Rescue also organized emergency response teams in Somalia and Lebanon.

Read more: Syrian White Helmet rescuers say thousands of volunteers need help

White Helmets: Neutral rescuers or spreaders of propaganda?

Watch video 03:06 Share Syrian White Helmets risk death in Idlib Send Facebook google+ Whatsapp Tumblr linkedin stumble Digg reddit Newsvine Permalink https://p.dw.com/p/3O6Rp Syrian White Helmets risk death to save lives in Idlib

The volunteers working as part of the White Helmets are acknowledged to have saved thousands of lives during the eight-year Syrian civil war, and the group maintains that it is neutral, because it provides assistance to both sides in the conflict.

However, the Syrian and Russian governments have long viewed the group as promoting Western propaganda and supporting anti-Assad insurgents.

Its first responders often risk death from "double tap" bombing raids by Syrian government forces, who launch secondary bombing attacks on the volunteers once they head into bombed buildings to search for survivors in the rubble.

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kmm/msh (Reuters, AP)