The person who recorded the row between outgoing National MP Nick Smith and a staffer no longer works at Parliament.
After 30 years, Smith abruptly threw in the towel on his political career on Monday, citing the loss of the Nelson seat and a Parliamentary Service inquiry into a "verbal altercation" in his Wellington office.
Smith said the investigation into the spat that happened last July is ongoing and the best course of action was for him to resign.
He was also under the impression details of that inquiry had been leaked and would hit the headlines on Tuesday, but no such story has appeared and it's not clear why he was told one would be coming.
Other than her Wednesday morning media round, National leader Judith Collins has refused to speak to journalists about Smith's resignation and the investigation this week, only responding to written questions through her media team.
RNZ, however, managed to question Collins as she was leaving a kiwifruit pack house in the Bay of Plenty on Thursday afternoon.
She refused to say if she or anyone from her office had advised Smith a media organisation was set to run a story about the investigation.
"I don't discuss the details of what I've said or not said to MPs but Nick Smith is absolutely clear that at no stage was he ever told to leave Parliament."
When asked by RNZ who she believed told Smith about the story if her office hadn't, Collins refused to speculate.
"I think it's really important I don't go down the path of trying to work out who's done what, where and how. But I'm very clear that if I ever hear of any media interest in any of our MPs I will always let them know. I think that's the right thing to do. It would be just unheard of for a leader not to tell an MP.
"As to the discussions I've had personally with Nick I can say he's feeling good and we're looking forward to hopefully having him come back next week."
Collins has previously told media the Parliamentary Service was alerted to the argument by a staff member of another MP who recorded the spat and then made a complaint.
Without some form of defence the recording would likely be illegal, Collins told RNZ.
"Having said that, I'm just giving you my legal advice on it. The second thing is that, of course, I've never heard it, don't know the details and haven't been advised of all the details."
Collins said she didn't know the person who made the recording personally.
"I don't know the person myself. I probably would if I were to see the person."
The person no longer works for the National Party or Parliamentary Service, Collins said.
It is not clear when the staffer left Parliament and under what circumstances.