A man has been arrested on suspicion of conspiracy to murder a Syrian preacher found shot dead in a car in London.
Abdul Hadi Arwani, 48, was found slumped at the wheel of his VW Passat in Wembley, north west London, with gunshot wounds to his chest.
The cleric was said to be a vocal critic of President Bashar al Assad and was reported to have been "sentenced to death" in the country for photographing a site of a massacre in his hometown of Hama in 1982.
Metropolitan Police have said a 36-year-old man has been arrested on suspicion of conspiracy to commit murder. He remains in custody at a central London police station.
A spokesperson said: "Detectives have established that Mr Arwani had driven near to the scene around mid-morning on Sunday, 5 April 2015, and had been parked up in Havenwood where he had remained for a short while.
"Officers are appealing to anyone who was in the area on Sunday 5 April or Tuesday 7 April to contact police.
"They are particularly keen to speak to anyone who may have seen Mr Arwani or his car."
Detectives from the Counter Terrorism Command are leading the investigation and officers remain "open-minded" about the motive.
Abdulhadi Arwani's son, Murhaf Arwani, has appealed for people to help the police in their investigation.
He said: "The police are currently investigating this brutal murder. As an individual, a family and a community, we are helping the police to solve this heinous crime. Any information we have has, and will be passed on to them and we urge anyone with any information to please please, please do the same.
"To members of the public that knew my late father and even those of you who didn't know him, please tell us what you know. We know that it won't bring our father back to us but it may help to deliver justice to those who killed him."