In the early hours of DECEMBER 13th, 1991, an anonymous caller phoned the police, saying that a body was hanging on London’s Hampstead Heath. This was no hoax, for at around 8 a.m. a woman walking her dog found a man hanging from a tree in Hampstead’s West Heath Road.

The man had been tied up with a washing-line, blindfolded with a red silk tie, and his briefcase lay open nearby. He was identified as Ghebre Luul Kassa, an Ethiopian refugee, and the police learned that he had last been seen alive at 6 p.m. the previous day, when he left a cafe in Cricklewood run by his brother. He had landed a job as chauffeur to a rich Arab family, he had told his brother, and he had made a number of phone calls from the cafe to a garage where his boss’s Mercedes was being serviced.

His gold ring inscribed with the letter “K” was missing, and his murder was believed to be a mugging gone wrong. Neither the Arab nor the garage Kassa had phoned could be traced, and when a recording of the anonymous phone call made to the police was played on BBC TV’s Crimewatch, nobody recognised the voice. The case remains unsolved.