Obvious questions

The Cons' claim about the NDP caucus call which someone is acknowledged to have covertly listened in on and taped:

A spokesman for the Prime Minister's Office said there was nothing unethical about covertly listening in to the private NDP deliberations, taping those discussions and releasing them to the media.

An unidentified Tory was "invited" to participate in the call, said PMO spokesman Dimitri Soudas.

So...was it somebody in the PMO who's claiming to have been invited in on the call? If so, then who? And if anybody had a valid invitation, why would they have needed to be covert listening it?

If not, then who provided the tape to the PMO for distribution? And then the questions can be asked down the line to figure out who was involved in taping the call.

Unlike Cadscam, the Cons can't plead that anybody involved is no longer alive to offer up answers. So we should expect either some details in a hurry, or some serious consequences for anybody who had any involvement.