Syria's Bashar Al-Assad
Syria's Bashar Al-AssadReuters

Syrian exile and imam Abdul Hadi Arwani was shot dead on a London street this week, and authorities now say his death may be a politically-motivated assassination. 

London police did not explicitly announce Arwani's death, saying merely that a man in his late forties had been found lifeless in his car on Tuesday, with gunshot injuries to the chest. 

According to the Wall Street Journal, it was Arwani's friends who confirmed him as the victim publicly; a police source confirmed it to the Daily Mail as well. 

Arwani, 48, was a staunch opponent of Syrian President Bashar Assad, and was involved in violent protests against the regime leader in 2011. 

The cleric was witness to the violent 1982 Hamas massacre by the Syrian Army under Assad's father, Hafez al-Assad; up to 40,000 civilians are estimated to have been killed in those events.

Arwani was deeply affected by the massacre; he was given a death sentence for photographing the carnage and damage, and his family fled Syria for the UK shortly after that. 

The cleric recently stepped down - or was forced to step down, according to some sources - as imam of the An-Noor Mosque in Acton, West London, after the mosque was associated with extremism and Islamism. 

But several associates insisted to the Daily Mail that Arwani was a moderate Muslim who shunned extremism and was a down-to-earth, mild, modest person who was a prominent community leader in London. 

A police source told the Mail that the killing appeared to be a "state-sponsored assassination" - and the mosque's reputation may have preceded him. 

Terrorist Mohammed Ahmed Mohamed changed in the mosque into a burka and fled, and has been missing since 2013. 

Uthman Mustafa Kamal, the son of hate preacher Abu Hamza, has regularly led prayers at An-Noor as well; another preacher delivered an infamous anti-Semitic sermon there in 2012. 

Police have asked the public to come forward with any information on the case.