The BBC's Greg Barrow reports from George, where PW Botha is on trial.

Officials from the Truth and Reconciliation Commission have been trying to demonstrate that the former South African President, PW Botha, has been evasive in written answers submitted to explain his role as chairman of the State Security Council during the 1980s.

They called two witnesses to a bomb explosion at the headquarters of the South African Council of Churches in Johannesburg in 1988.

The witnesses explained that although there were no fatalities, the explosion caused widespread distress among local residents and resulted in many injuries from flying glass and masonry.

The South African Council of Churches played a high profile role in the anti-apartheid struggle during the 1980s. Senior security force personnel have already testified to the Truth and Reconciliation Commission that the bomb was planted at the request of the State Security Council headed by Mr Botha.

But the former president has refused to answer questions about the explosion. He argues that it falls outside the remit of the Truth and Reconciliation Commission because nobody was killed.