A convicted South African security force assassin has told a court trying a case against the former president, PW Botha that government leaders during the apartheid era encouraged him to carry out attacks on black activists.

Eugene de Kock, a former security force colonel, was giving evidence in the trial of the former President, PW Botha, who's charged with contempt for refusing to appear before the Truth and Reconciliation Commission.

He accused National Party politicians including Mr Botha of being too cowardly to answer to their role in state-sponsored violence.

De Kock - notorious security force killer

Eugene de Kock - who is serving more than 200 years in prison for his role in the murder of government opponentsis - seen as the living embodiment of state-sponsored violence in apartheid South Africa.

As a commander in the counter-insurgency unit of the security forces in the 1980s, he became an accomplished state assassin - a man who's been nicknamed "Prime Evil".

In court he exploded the myth that senior National Party politicians including the former president knew nothing about operations to attack and kill black and white activists from the African National Congress and other opposition groups.

De Kock said that he and other security force operatives had been sold out by the politicians who encouraged their actions during the apartheid era.

They wanted to eat lamb, but they didn't want to see the blood, he told the court; and he went on to describe the politicians, including Mr Botha, as cowards who'd have to answer to their crimes before God.

De Kock said the politicians had incited and goaded him into carrying out attacks during the height of the apartheid era.