A Syrian preacher from a west London mosque has been found shot dead in a car in Wembley.
The preacher, in his late 40s, was discovered in the vehicle at 11.15am. An air ambulance was called, but he was declared dead at the scene.
Detectives launched a murder investigation and said they knew the identity of the victim, but that formal identification had not yet been completed.
Sources confirmed it was believed to be Mr Arwani, a preacher at the An-Noor Mosque in Acton, west London.
The mosque has previously hosted the son of radical preacher Abu Hamza, and was the location for the November 2013 escape of terror suspect Mohammed Ahmed Mohamed, who dressed himself in a burka.
A police source said the mosque had attracted a number of former criminals who have turned to Islam and it was possible that a feud at the mosque had turned violent.
Mr Arwani was advertised as a speaker at an event at the East London Mosque last June and listed as speaking from Syria.
He is said to be a staunch critic of the Bashar al Assad regime.
Supporters posted messages to the preacher on Twitter.
One read: “Just received the news Sheikh Abdul Hadi has been murdered. May Allah grant him jannatul firdous [paradise].”
Another said: “Former imam of Masjid an-Noor in Acton, Sheikh Abdul Hadi Arwani has been found shot dead in his car. May Allah have mercy on him and accept him.”
The An-Noor Mosque has hosted fundamentalist speakers including Murtaza Khan, Shakeel Begg and Haitham Haddad.
Scotland Yard’s Homicide and Major Crime Command has appealed for anyone who may have seen Mr Arwani’s car in the Wembley area on Tuesday morning to get in touch.
A spokesman said: “At this very early stage detectives retain an open mind regarding the possible motive.”