Waleed Aly

Paul Brereton, the outgoing head of Australia's National Anti-Corruption Commission, was grilled at Senate estimates this week.

Brereton led the body tasked with investigating serious corruption in the Commonwealth public sector.

But his time as its first commissioner has ended in a crisis of confidence over robodebt, his ongoing defence links, and whether the watchdog properly managed conflicts of interest inside its own walls.

Brereton says he's become a distraction from the Commission's work, but his resignation begs the question, do the NAC's problems end with him?

I'm Will Ed Ali.

You're listening to 7am.

Today, independent journalist Nick Fyke on how Australia's anti-corruption watchdog ended up in crisis and whether it can recover.

It's Friday, May 29th.

Nick, that was quite a showdown, I think you can say, between Paul Brereton and some senators in the Senate Estimates Inquiry.

But before that, I want to go back to 2016 with the Brereton Inquiry into war crimes in Afghanistan, because that's intimately involved, isn't it?

It is.

So tell us about what we saw on Tuesday night in Senate Estimates.

Was there anything that stood out to you from those exchanges?

Okay, so three investigations is quite a lot to get your head around.

Do we know much about them?

Can we separate what the three are about and whether or not they're related?

So let's talk about this concept of a conflict of interest here.

If Brereton is connected with the ADF in some kind of formal way, and there have been photos circulating of him wearing army fatigues, for example, while he was commissioner, the conflict of interest there is what?

That there might be some kind of corruption allegation that emerges from the Defence Force itself?

And that if so, how?