News International's hacking saga continues to throw curve balls.

Speaking on Sirius XM's Media Matters Radio show, Guardian writer and press critic Roy Greenslade alleged the Murdoch-led company had been spying on British MPs who were investigating the conduct of the paper in this summer's "hackgate" scandal.

Here's the full exchange with host Ari Rabin-Havt (with added emphasis), via Media Matters:

ARI RABIN-HAVT (co-host): Roy, do you think that News Corp. is a criminal enterprise. To be pointed about it.

GREENSLADE: I think, you know, in truth, it would be way over the top for me to say that. And I was equally distressed that Tom Watson had referred to the Mafia. But, you know, one can understand why he did, for goodness' sake. When we talk about omerta, we talk about a code of silence. Well, for several years, News International, which is the U.K. division of News Corporation, has maintained a code of silence. They have lied, they have deceived, and they have briefed private eyes to follow people. And in Tom Watson's case, you can understand why he was incredibly angry to find that he's been under secret surveillance for several occasions.

And I can add a little to what Steven said, because I do have a source who was in The News of the World, the newspaper that was closed after this debacle. And he tells me that for three days, only six, seven months ago, every single member of the parliamentary committee investigating this matter were followed by private eyes and/or members of staff of the newspaper. And only after some of the staff protested that they didn't want to do it did the -- were they called off.

Now, that goes even beyond what we've previously heard. And I've only just been told this in the last 24 hours, so your audience is getting a scoop here.

RABIN-HAVT: So, are we breaking a little news here?

GREENSLADE: You are breaking a story. I wish I could name the source, but, of course, I have it confidentially.

Here's the audio:

Why would News International want to spy on these people? Well, the obvious answer, of course, is to find some dirt that they could then use to apply pressure — yes, that is basically blackmail.

Tom Watson, a prominent critic of Murdoch on the panel, has said he is now seeking legal advice.

