The teenager's family saw this computer image

The victim's body was seen being bundled into the back of a lost or stolen white Nissan Micra, registration number H767 HEW.

Police are appealing for people who may have seen the car driven north along Ealing Road to come forward.

Witnesses have said there were at least two other men in the car.

Police believe the petrol used to burn the body could have been bought from a garage in the Wembley or Kingsbury area in the days leading up to the murder.

Detective Superintendent Nigel Mawer said: "We would like everyone to concentrate their minds once more on these new points of appeal."

Second body

A post mortem revealed the teenager, who lived in Wembley, had been battered around the head with a weapon before being doused in petrol and set alight.

The burns to his body were so severe that it made it difficult to establish what the victim looked like before the killing.

The three men questioned in connection with the incident were all Asian, and aged 21, 19 and 17 years.

Meanwhile, detectives investigating a second murder where the corpse was set alight believe they know the identity of the dead woman.

They believe the woman, whose body was found on fire at 0015 on 5 March, could have been a woman from Balham, south London who was reported missing.

Four men have been arrested at an address in Balham and released on police bail until April in connection with the inquiry.