Now we know why: what was until this week a low-level controversy has quickly exploded into a full-scale scandal on the eve of the March state election.

The reputations of two of the state's most senior police – Commissioner Andrew Scipione and deputy commissioner Catherine Burn – are under a cloud due to their involvement in an internal affairs unit accused of illegal bugging, possibly to settle old scores.

A third, deputy commissioner Nick Kaldas – the target of the bugging operation – has used the inquiry to seriously impugn the reputation of that unit and those involved in it.

He has also issued a scorching review of NSW Ombudsman Bruce Barbour, whose office is supposed to be one of the most trusted in the state.

Baird argued last year that the inquiry would interfere with the work being done by Barbour. His inquiry, Operation Prospect, was established in 2012 with a view to finally getting to the bottom of the long-running police bugging saga.

But two years on, no report was forthcoming, prompting Labor, the Greens and the Shooters and Fishers Party to take the matters into their own hands last year.

Baird and his senior ministers argued that the parliamentary inquiry would interfere with Barbour's ability to do his work.

But given what is emerging, coupled with the furious attack on Barbour's reputation by the respected Kaldas, this excuse rings very hollow.

The evidence of Kaldas and other witnesses – including journalists Steve Barrett and Neil Mercer – that Barbour is improperly focused on rooting out who leaked sensitive documents that first led to the exposure of the Mascot's wrongdoing – has seriously undermined whatever finding his inquiry may  produce.