Police are urging a witness they think could be the key to solving the murder of an innocent student, gunned down in a parked car, to come forward.

The final moments in the life of teenage Nigerian prince Joseph Burke-Monerville, who was brutally shot in the head earlier this year, were recreated on BBC’s Crimewatch last week – as a £20,000 reward for the information which leads police to his killers was announced.

The 19-year-old of Canonbury Square, Islington, had spent the evening at the gym with his identical twin Jonathan and elder brother David before the horrific attack – thought to be a case of

Following last Thursday’s TV show, which also included moving appeals from the Burke-Monerville family, charity Crimestoppers received an anonymous call from someone with evidence which police think could be crucial in tracking down those responsible for the fatal shooting – but detectives need to speak to the person directly.

Det Sgt Mark Romain, leading the investigation for the homicide command unit, said: “We had somebody phone Crimestoppers just after the show with some significant information. We’d like the person to contact us directly in confidence so that we can develop the information. We have vast experience of managing confidential information and ensuring that the people who provide it are not put in any danger or are exposed.”

The Crimewatch re-creation shows how the three brothers were approached by two masked men who asked if they were from “Pembury” [the estate near to the scene of the killing].

When David explained that they didn’t live in the area and that his twin brothers had just returned from Nigeria, the clip showed the men discuss what to do before one of them said “light them up” and fired three shots into the vehicle.

They then made off along Pembury Road and on towards Hackney Downs.

Describing the horrific attack, Jonathan said: “I didn’t really see the first shot, I just heard it. Then I heard another shot. I heard David scream and then heard the third shot – I didn’t know what had happened.

“That shot grazed my arm, then I looked over at Joseph and he was not in a good state. There was blood coming out of his mouth, then his nose and his ears. It was terrible. Even talking about it as I remember it hurts.”

In frantic scenes, the recreation showed how David, who also had a bullet in his arm, started driving away from the scene and pulled over to call for help when he spotted a police car.

Jonathan said: “All I could do is pray.”

Joseph was taken to hospital where he was later pronounced dead.

Paying tribute to his brother, Jonathan added: “He was the best person I’ve ever known in my life. He was fun, loving, caring and hard- working. He was a perfect person. There’s a hole in the family, a big hole, and it can’t be filled.

The first suspect is described as black and the second as light-skinned – possibly of Asian or Turkish appearance.

They were wearing dark hooded tops, with bandanas covering their faces.

Any witnesses or anyone with information can call the incident room on 020 8345 3985.