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 underway 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 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.”