The 80-year-old mother of a man who was burned to death has appealed for witnesses to help unravel the "horrifying circumstances" surrounding how he died.
Bus driver Kester David, 53, was found under a railway arch in Palmers Green, north London, in July 2010 but the gruesome end to his life has remained unexplained.
His mother, who has asked not to be named, said: " When the detectives informed me that the burnt body of a bus driver had been found, the one thing I hoped in my heart was that he was already dead when he was set alight. No mother should have to bury their child under such horrifying circumstances.
"I appeal to anyone out there who may have heard his cry for help or seen anything unusual on the night of 6-7 July 2010 to come forward however small the information. I am sure a third party was involved and they must be stopped from doing this again."
Mr David worked part-time for Arriva from their Wood Green depot, and was also a DJ, using the stage name DJ Bain. He worked for an internet radio station in Stoke Newington called Lynx Radio for a short time before he died.
The fitness enthusiast, who was killed by burns and inhalation of fumes, was found under a railway arch at Broomfield Lane in Enfield that can only be reached by climbing over a metal fence.
CCTV from a nearby Travis Perkins yard captured a bright light coming from under the arches in the early hours of the morning before Mr David was found, and witnesses heard screams at that time.
Detective Chief Inspector Noel McHugh, said: "Kester was a hard working, well-respected individual in his local community and I am committed to finding out why he died. Despite continued efforts to identify the circumstances surrounding Kester's death, it remains unexplained and we appeal to anyone who can assist with information to come forward.
"Kester's mother is now 80 years of age and one can only imagine the agony she has endured since July 2010 not knowing why her son died."
His family have been fiercely critical of the initial bungled investigation into his death, and have accused Scotland Yard of racism.
Detectives, who are issuing an appeal for information tonight on BBC's Crimewatch, are trying to trace Mr David's movements in the days up to his death on July 7 2010.
They are looking for a unidentified man who answered Mr David's mobile phone on July 5. The Blackberry Curve was also used after he died, on July 14, 15 and 22, but has never been found.
Two weeks after his death, a woman called Sharon emailed police to claim that she knew who had killed him, but officers have never found her.
Anyone with information can call police on 020 8785 8099.