He admitted that my father’s neighbour, a man called Jack Tubb, was one of his agents, and he spoke freely of his close relationship with the Tubb family. I’ve met him twice and each time the smell of alcohol from him hit me from several metres away. I’d been taken there by McPherson, an ex-security policeman who had been in charge of observing my father’s house. McPherson is a thin man with a whining voice and a shifty, crab-like gait.

Three weeks ago Earle was jailed for corruption.Then there’s Vic McPherson. A couple of Christmases ago I found myself in the livid-pink interior of the John Vorster Square Officers’ Club in Durban. I’m sure he was lying and that someone ordered him to shut the investigation down when he got too close to Dolinschek and BOSS It all reeked of a cover-up. Chris Earle was the investigating officer at the Durban police’s murder and robbery department in 1978.

I came back to see him in 1995, when he was a Brigadier in Krugersdorp.He was still convinced that the murder was not a political one. I said that, given the circumstances, this was a ludicrous suggestion His hands shook, but he stuck firmly to his story. An ex-cop told me that he had heard, through friends in the security police, that a man called “Rooibaard” had boasted about killing myfather. According to my source this Rooibaard was killed in a mysterious single-vehicle accident around April 1978.

The source suspected that he’d been murdered in order to shut him up. I went back to London to edit the film, knowing only that South Africa was still a place where assassins could hide.Whoever killed my father had the best assistance in covering their tracks. In 1993 I found him in Zambia – in African National Congress “custody” We talked for several hours. He said he didn’t do it and I believed him, but I was sure he knew more than he told me. Dolinschek is now a senior manager in the National Intelligence Agency (NIA), the present-day equivalent of BOSS There was one fresh lead. He was sorry but he couldn’t help me.In the 1980s my grandmother had pursued BOSS agent Martin Dolinschek all the way to the Seychelles.

He said the murder was a great mystery which had long puzzled him. I said it was unlikely that he had never heard even the slightest rumour about who the killer might be. Taylor finally admitted that “it might have been one of our guys, but we kept our noses out of each other’s business”. Taylor was a security policeman who used to come to our house, checking up on my father before and after the banning So I called Taylor and asked to meet him He refused. Too many people have mentioned the name Andy Taylor in connection with my father for it to be mere coincidence. He said he didn’t know who killed my dad, but after that meeting I cried with horror at the realisation that we were connected, Dirk and I. We were all too intimately bound up by the violence that he had perpetrated and that my father had fallen victim to.