Abdul Hadi Arwani, a preacher at the An-Noor Mosque in Acton, west London, was found sitting in a dark-coloured Volkswagen Passat car in Greenhill, at the junction with The Paddocks in Wembley, with a gunshot wound to his chest on the morning of 7 April.
Arwani who is believed to be in his late 40s was found in the car at 11:15am local London time.
An air ambulance was called but Arwani was pronounced dead at the scene just over half an hour later at approximately 11:48am, reported Sky News.
A murder investigation has been launched by detectives who confirmed the identity of the victim but a formal identification is yet to take place.
A post mortem examination will be launched into Arwani's death in due course, said the Met police.
"At this very early stage detectives retain an open mind regarding the possible motive," said a police spokesman.
Scotland Yard's Homicide and Major Crime Command is appealing to anyone who might have seen Arwani's car in the Wembley area 10:00am onwards on 7 April or anything suspicious to get in touch.
The An-Noor Mosque has been accused of hosting several radicals, including the son of radical preacher Abu Hamza.
Terror suspect Mohammed Ahmed Mohamed is also believed to have taken refuge in the mosque dressed in a burka in 2013.
According to a police source, a possible feud at the mosque could have driven the murder.
Arwani, known for his criticism of the Syrian president, Bashar al-Assad, studied in Jordan and moved to the UK where he taught in Slough and West London, according to the London College for Islamic Studies.
Arwani's supporters have taken to Twitter to pay their tributes to the late preacher.