Police investigating the murder of a father shot dead during Croydon's riots have interviewed more than 600 people as they hunt for his killers, an inquest has heard.

Trevor Ellis, 26, died after being shot in the head following a high-speed car chase while looters rampaged through the town on August 8, 2011.

The police officer leading the investigation yesterday said police were no closer to learning who killed the Brixton dad-of-four in Duppas Hill Road.

Detective Inspector Alison Hepworth told Croydon Coroners' Court: "Six-hundred people have been interviewed and we have made extensive CCTV inquiries, but it was a night of unprecedented violence in Croydon, so a lot of CCTV was directed that way.

"What we need is for someone to come forward."

Coroner Roy Palmer recorded a verdict of unlawful killing after Det Ins Hepworth said she was certain the killing - in which a black man approached Mr Ellis's car, which was boxed in, and shot him from three or four metres away - could not have been an accident.

Dr Palmer said: "The hope is that one day some one will come forward but at the moment there is no prospect of that."

Speaking after the inquest, Mr Ellis's sister branded a witness - a friend of her brother - who could hold the key to solving the murder a "coward" after he stopped co-operating with police.

T-Boss Ellis Senior, 45, said: "If people know something and are not coming forward, well, I just hope the same thing wouldn't happen if it was their family.

"Some people might say it's fear stopping people from talking, but I call it cowardice."

Of the inquest, she said: "This feels final now, like the end, but it is not. There is nothing more we can do but we know the police will not stop."