The heavy-handed fashion in which President Thabo Mbeki and Justice Minister Penuell Maduna have handled the exclusion of the special investigating unit headed by Judge Willem Heath from the arms procurement investigation has caused public consternation.

The question is why it is of such importance to the executive arm of government to break Heath's authority over the unit or, failing that, to disband the unit itself. Why should they choose to incapacitate the unit at the precise time when its special powers and proven skills could play a central role in investigating alleged impropriety in the multibillion-rand arms deal?

Government's exclusion of the unit from this investigation elicits two important questions yet to be adequately answered.

First, what would ordinary people stand to lose if the deal were to be seriously compromised through impropriety? Second, what contribution could the unit make to the investigation that could not be made by the other bodies involved (the public protector, auditor-general or directorate of serious economic offences)?

It is important to note that the total value of the arms deal is not R43,8bn the figure that has been repeated incessantly over the past few weeks. The real value of the deal is R104bn. This is the amount of money that government reassured the public it would obtain to "offset" its expenditure of R43,8bn of public money on armaments instead of social upliftment.

Although there is no prima facie evidence of criminal misconduct at this point, questions have been raised about the integrity of the procurement deal both in terms of the awarding of the primary contracts and in the subsequent awarding of subcontracts. These questions have been posed in good faith by the auditor-general's office and Parliament's standing committee on public accounts.

Mbeki's insistence that any potential impropriety in the deal should be measured against a criminal standard of proof misses the point. The fact is that most of the contracts making up the arms deal have already been signed between the various parties. So the limits of any criminal investigation into the procurement process would be reduced to establishing the prevalence of extortion in the awarding of contracts or, alternatively, fraud and theft subsequent to the contracts having been signed.

In the absence of uncovering any common-law crimes the criminal investigation would remain silent on the crucial question of the integrity of the contracts entered into by the state in the first place.

Consequently, it would not address the most important concerns of ordinary South Africans the question of whether the public interest was met by awarding the primary contracts to the most cost-effective tenders, and whether the "offset" benefits at the level of the awarding of subcontracts will be realised in the form of jobs and economic development.

If contracts were awarded to subcontractors on the basis of family ties (nepotism), or personal/political ties (cronyism), this would call the integrity of the entire deal into question. These actions, however, do not constitute the common law (criminal) offences of fraud and theft. In terms of civil law, however, the possibility exists to have the contracts set aside if it can be proven on a balance of probabilities that they were entered into contrary to the interests of the public.

While it might be said that the office of the public protector has similar powers in terms of the Public Protector Amendment Act, which enable it to investigate any alleged "improper or dishonest act, or omission or corruption, with respect to public money", there is a crucial difference between its powers and those at the disposal of the unit once its investigations have been completed.

In terms of its guiding legislation the public protector cannot initiate court action as a result of its findings. It is limited to making a recommendation to the relevant prosecuting authority (in criminal matters) or to the appropriate public body (in respect of disciplinary or civil proceedings). The unit, on the other hand, has the power to initiate civil proceedings before its special tribunal.

The unit has also acquired considerable forensic expertise in the course of its investigations into procurement processes. It has successfully managed to have some of these procurement contracts set aside in the special tribunal.

The unit's powers to pursue civil court actions, to recover public funds and prevent losses to the state are not unique. The state attorney, however, can initiate civil proceedings only on the instruction of the executive. In the case of the arms deal the executive has consistently denied the existence of impropriety. So it is unlikely that the executive would issue such an instruction in the first place.

But, even if an instruction to initiate civil proceedings was to be issued, the state attorney is at a considerable disadvantage to the unit. The proximity of the unit to the special tribunal gives it a capacity to speedily and efficiently initiate civil proceedings in ways that the state attorney is unable to match.

This, taken together with the forensic investigative experience and powers of search and seizure that the unit has at its disposal, provide it with a unique set of abilities to defend the state and public against potential improprieties in the handling of public resources.

With acknowledgement to Colm Allan, director of the Public Service Accountability Monitor, Rhodes University and Business Day.