Correspondent Jane Standley: "Dr Basson knows time is on his side"

Dr Basson - nicknamed "Doctor Death" - told a hearing in Cape Town that western governments had given him secret information which had helped him set the programme up in the early 1980s in return for South African intelligence about Soviet capability.

But he denied allegations that he had spearheaded research into poisons and viruses that would kill only black people.

He said that at a 1981 meeting in Texas he had received "an incredible amount" of information from American, German, Japanese, Taiwanese, British and Canadian military scientists.

Race against time

The commission has now officially ended its work after more than two years of hearings and investigations into human rights violations committed during the apartheid era.

Dr Basson's testimony came after two days of delay, when his lawyers argued that he should not give evidence because it could prejudice criminal charges against him, including conspiracy to murder.

The BBC Southern Africa correspondent says the commission was engaged in a race against time to get information from Dr Basson before midnight.

He was told to answer all the commission's questions by the end of the day, or risk being sent to jail.

Bacteria against blacks

Dr Basson denied allegations made by his former colleagues that he masterminded a programme in the 1980s to develop chemical and biological weapons to be used against black people and anti-apartheid protesters.

In a written statement, he said that South Africa's chemical and biological weapons programme was developed in response to the alleged use of chemical weapons by Cuban troops supporting the Angolan Government against South African soldiers.

He also denied he had been involved in a plan to poison Nelson Mandela in prison.

He told the Truth Commission that in the 1980s he and apartheid's leaders actually protected the then imprisoned Mr Mandela from an assassination plot by radical black activists.

In an extended session of the hearing, Commission investigators continued to question Dr Basson after his lawyer had left.

They quizzed him on allegations that apartheid government scientists had produced drugs, including Ecstasy, and then sold them on the streets of South Africa.