In its submission to the Truth and Reconciliation Commission the ANC expresses the suspicion that three of its senior officials may have been subverted by apartheid operatives and later, when their suspected perfidy was in danger of being detected, poisoned to prevent them from exposing a more deeply embedded spy network.

The three ANC men were Solly Smith, who served the party as its chief representative in London; Francis Meli, editor of the ANC journal Sechaba; and Muziwakhe Ngwenya, an ANC regional military commander who was known as TZ after the initials of his guerre de nom, Thami Zulu.

Smith and Meli died in South Africa in 1993 and 1991 respectively after their return from exile. Both were suspected by the ANC to have been poisoned by operatives of the previous regime. The evidence was inconclusive, however.

TZ died in exile in Lusaka, Zambia, shortly after his release from detention by the ANC security department. A large well-built man, he emerged from detention in November 1989 in a frail and almost unrecognisable state. He was suffering from tuberculosis aggravated by Aids, according to the report by the ANC commission of inquiry into his death handed to the TRC.

But, significantly, medical analysis at the University Teaching Hospital in Lusaka showed traces of the pesticide diazinon in specimens of his blood and stomach contents. From that the ANC commissions concluded that there was a strong likelihood that TZ had been poisoned as well.

The detention and death of TZ is worth examining in greater detail for the perspective it offers on the current controversy over allegations that the National Public Prosecutions Director, Bulelani Ngcuka, might have been recruited as an agent of the white government in the 1980s.

TZ was one of the many young blacks who left SA for military training abroad after the student rebellion of 1976-77. He joined the ANC and, having won a reputation for bravery, became a commander in its guerrilla army, Umkhonto weSizwe, first in Angola and then in Swaziland, where he was responsible for the guerrilla campaign in what is today KwaZulu Natal.

It was as commander of the Natal Machinery - to use ANC terminology - that he was detained on suspicion of being an enemy agent. The main reason for his detention was the heavy losses suffered on the Natal front and, in particular, the ambushing and killing at point-blank range of an infiltrating squad of nine guerrillas (including three women) by security forces of the former South African state.

TZ was detained for 17 months, during which he was interrogated by ANC security, before being released in an emaciated state on November 11 1989. He died five days later. The ANC military leaders were deeply perturbed - Chris Hani, its chief of staff, particularly so. They had retained confidence in TZ despite the suspicions of the ANC security department.

On the question of whether TZ was a South African government spy, the ANC commission of inquiry concluded on the evidence before it that he was a suspect and no more. It added, however, that information might come to light in the future that proved or disproved the suspicions conclusively.

Expatiating on its belief that TZ was probably poisoned, the commission reckoned:

The person or persons who administered the poison had to be enemy agents whose motive was either to silence TZ before he gave the game away or to provoke enmity between the ANC's military and security branches.

The poison would have had to be given to him a day or, at the most, two days before his death, as diazinon cannot be stored in the body and would have been excreted if it had been introduced into his system earlier.

But, as Paul Trewehela noted in Searchlight South Africa (No 11), the commission did not address the question of who had access to TZ during those last two days of his life. The information should not have been too difficult to obtain. It was known precisely where he spent his last days.

There was another important clue: one of those who saw him during the last days of his life gave him three bottles of beer, in which diazinon is soluble.

The ANC specifically requested the TRC to investigate which agents of the former government were reintegrated into networks of the state when the ANC resumed a legal profile in SA and what activities they were involved in.

Burdened with the enormous task of establishing what gross human rights violations were committed during a period of more than 30 years and of identifying the perpetrators, the TRC was unable to provide the information.

The questions, however, seem as pertinent today as they were when presented to the TRC seven years ago, perhaps even more so in light of the quarrel between Ngcuka and Deputy President Jacob Zuma. The latter, as the ANC chief of counter-intelligence in the 1980s, presumably would have acquainted himself with the minutia of the TZ case and, more broadly, the threat in Trewehela's words of real patriots being hunted down as enemy agents while real enemy agents urged on the hunt.

Judging from his Letter from the President in the October 3-9 edition of ANC Today, President Thabo Mbeki thinks the questions have been made superfluous by the ANC's decision to voluntarily work with the historical party of apartheid - the National Party, aka the New National Party - in the interests of promoting a wider national unity.

But, on the face of it, that represents a departure from the position taken by the ANC in its 100-page statement to the TRC in August 1996.

It appears to blur the distinction between the ANC's National Party enemies who came to the negotiating table as a sign of their desire to work for the common good - and who served in the government of national unity for more than two years after the April 1994 general election - and the scheming spies within ANC ranks who declared their loyalty to the struggle while secretly working to subvert it.

That aside, TZ's family has a right to know whether an enemy agent posing as a righteous friend murdered him. So, too, do TZ's comrades in Umkhonto weSizwe who stood by him during his ordeal.

With acknowledgements to Patrick Laurence and The Star.