LONDON (AFP) - A Syrian man living in Britain described as a prominent activist opposed to President Bashar al-Assad was found shot dead in his car in north-west London, the BBC reported on Wednesday.

The police were called by paramedics after a man was found with what were thought to be bullet wounds to the chest, the broadcaster said.

"The BBC understands the victim was Abdul Hadi Arwani, a chef and former imam at a London mosque," it reported.

London police did not confirm the identity of the victim, but said a murder investigation was under way after a man in his late 40s was found dead in a car in Wembley, north-west London on Tuesday.

"Detectives believe they know the identity of the deceased, however, formal identification awaits," the London Metropolitan Police said in a statement.

"A post-mortem examination will be arranged in due course."

Friends and supporters of Mr Arwani paid tribute to him on social media, and former Guantanamo Bay detainee and activist Moazzam Begg wrote on Twitter: "May Allah have mercy on him."