WHEN the previous Victorian government first flagged the appointment of a US-style special prosecutor to bolster the fight against organised crime, The Age expressed its concern about the conferral of sweeping powers on a body that would not be subject ''to the normal checks and balances''. Tougher powers, this newspaper argued, were open to abuse, and ''not of themselves a solution'' to the problem of crime.

That was in 2004, when Melbourne's underworld feuding had turned bloody. The very existence of the body, let alone basic facts about its operation, was since scarcely noted on the public record, until yesterday's report revealing that 350 people have been called before the Chief Examiner. The witnesses summoned, by order of the Supreme Court, to give evidence about serious organised crime had no right to silence and could be jailed for up to five years if they refused to testify or give false evidence. Moreover, it is illegal for witnesses or their lawyers to discuss not merely the substance of the hearings, but even the fact they have taken place or are pending.

Police waging war against serious crime insist the examiner's office has helped crack the underworld's code of silence and enabled prosecutions that had previously been frustrated by witnesses stonewalling investigators. They cite several high-profile criminal cases in which evidence gained by the examiner was used. Police endorse the secretive and powerful body as a crucial weapon of last resort: if not a solution in itself, then at least a large part of one.

Only the most naive would suggest the fight against increasingly sophisticated crime networks, which thrive on intimidation and their own codes of secrecy, can be successfully waged without bolstering police powers. But the lack of transparency remains worrying.

It is unclear whether there have been adverse consequences for witnesses who have had their fundamental right to silence violated, or whether the examiner's powers are being used beyond their intended purpose. While technically the body is overseen by the Special Investigations Monitor, the public has no means of scrutinising the effectiveness or integrity of this process. The fact the monitor registered no complaints against the body in its last reporting period is of little comfort given the powerful disincentives for already vulnerable witnesses to expose their interaction with the system. We need more than assurances the body is wielding its powers cautiously.