Deborah Cornwall reported this story on Tuesday, February 10, 2015 12:20:00

ELEANOR HALL: New South Wales’ two top police chiefs are set to go head to head again today at an explosive inquiry into a 15-year-old police bugging scandal.

Deputy commissioner Catherine Burn was the first to give evidence this morning after her fellow deputy Nick Kaldas demanded that she return to explain her claim to the inquiry last week that she’d had good reason to go after Mr Kaldas in early 2000.

Nick Kaldas was one of dozens of policemen wrongly targeted in the botched sting operation.

Deputy commissioner Burn was clearly flustered this morning when presented with some inconsistencies in her evidence.

Deborah Cornwall has been covering the inquiry and joins us now.

Deb, just how explosive did it get today?

DEBORAH CORNWALL: Well look, there was certainly a lot of anticipation about deputy Burns’ evidence today because, frankly, when she was called back this morning, the primary reason was that in her evidence two weeks ago she left the very strong impression that even now, 15 years on, she still holds what she calls a reasonable suspicion that fellow deputy Nick Kaldas had been involved in some level of corruption.

Now that of course quite understandably outraged Mr Kaldas and his lawyers.

So that was the first issue that needed to be cleared up, and I think it’s fair to say even today deputy Burns struggled to concede she didn’t still hold a reasonable suspicion of Mr Kaldas.

But of course she did admit her own commissioner Andrew Scipione had last week cleared him of any charges and that if there were any questions about Nick Kaldas’ integrity he wouldn’t have made it to deputy commissioner.

But I do think it’s fair to say deputy Burn hasn’t exactly covered herself in glory at this inquiry.

She’s been extremely defensive about her role in this investigation and the allegations that she and other officers used illegal means to put wire taps on police and turned a blind eye to crimes committed by the main informant, a corrupt police officer called M5, who was mentally ill at the time of the investigation.

This is a grab that we have from the evidence this morning, when she’s asked again whether she realised – why it was that Nick Kaldas was the only name that had not been nominated by M5 yet still they went after Nick Kaldas.

DAVID SHOEBRIDGE: The only police officer who was proffered to M5 to seek to get some evidence of corruption from, the only officer was Mr Kaldas.

CATHERINE BURN: If that happened, I do not recall the context, and please, I would need to refer to the debrief to get that context and I think that is only reasonable and fair to ask that I would actually be able to have a look at that.