Police investigating the murder of a Syrian-born preacher in London have arrested a fourth person in connection with his death.
Abdul Hadi Arwani, a critic of the Bashar al Assad regime, was found shot dead in his car in Wembley on 7 April.
Scotland Yard said a 36-year-old man was arrested on Friday on suspicion of conspiracy to murder.
His arrest was only made public on Sunday, when he was released on bail.
Leslie Cooper, 36, appeared at the Old Bailey on Thursday charged with Mr Arwani’s murder.
Cooper, from Brent, was remanded in custody and will reappear in court on 28 April.
A 61-year-old man, who was already being held on suspicion of conspiracy to murder the imam, was re-arrested over terror offences on Wednesday.
And a 53-year-old woman was detained in Brent on Wednesday on suspicion of terror offences.
They both remain in custody at a south London police station.
Mr Arwani, a father of six, was an imam at the An Noor mosque in Acton, west London, between 2005 and 2011.
He is thought to have fled Syria as a teenager in 1982 after surviving the Hama massacre.
Mr Arwani is believed to have attended protests against Assad outside the Syrian embassy in 2012.