By Mohammed Allie
BBC News, Cape Town
An apartheid-era South African security police commander says ex-President FW de Klerk knew of gross human rights violations during his term of office.
De Kock was jailed over the killing of anti-apartheid activists
Eugene de Kock, jailed for his role in killing anti-apartheid activists, made the accusation a day after Mr De Klerk said that his conscience was clear.
Talking from his prison cell to a radio station, he said the ex-president's hands were "soaked in blood".
De Kock said he was prepared to testify in court against Mr de Klerk.
He said Mr de Klerk's hands were "soaked in blood", and claimed he could list exact instances where the country's last white president gave the order for specific killings.
De Kock was nicknamed "Prime Evil" for his role in ordering the killing and maiming of dozens of anti-apartheid activists, often using very cruel methods. He is serving two life sentences in a maximum-security prison in Pretoria.
On Thursday, Mr de Klerk denied ever condoning the elimination of anti-apartheid activists or any other gross human rights violations during his term of office, which began in 1989 and ended in 1994 when Nelson Mandela became president.
"I have not only a clear conscience, I am not guilty of any crime whatsoever," Mr de Klerk said while addressing the media in Cape Town.
"I have never myself approved murder or the random killing of anybody, or gross violations of human rights."
There has been speculation about Mr de Klerk's knowledge of human rights violations during his term of office since news first broke last week that his former Police Minister, Adriaan Vlok, would face charges relating to the poisoning of the then secretary general of the South African Council of Churches, Reverend Frank Chikane, in 1989.
Mr Vlok has admitted to approving the poisoning of the former church leader as well as other human rights violations.
He publicly sought forgiveness by washing Rev Chikane's feet in his office last year.