Prime Minister Bill English now says Todd Barclay offered to play him the recording of an electorate staffer when they first spoke of it.
Allegations that Mr Barclay, National's MP for Clutha-Southland, secretly recorded electorate staffer Glenys Dickson in the Gore office have cost him his political career.
Mr English has also come under intense scrutiny for his role in what began as a employment dispute, and has ended up a full-blown political scandal.
Mr English told police about a conversation he had with Mr Barclay last April during which the MP told him what he had done.
But he did not say exactly when that conversation had taken place.
Speaking after his annual conference speech in Wellington, Mr English told reporters Mr Barclay did offer to play the tape to him.
But he said he did not think it was "appropriate" to take Mr Barclay up on his offer.
"There was an employment dispute going on to which I was not a party to, and this was some time after I'd left the electorate," he said.
"I was not working with the staff, I had no official role relative to that dispute."
Mr English was asked how that squared with his previous comments that there was no evidence the recording of Ms Dickson existed in the first place.
"I haven't denied anything, I've just said that what I was told I then passed to the police when they asked me about it.
"There was then an investigation, at the conclusion of which no charges were laid."
He "simply didn't know" whether a recording existed or not, he said.
Police are reassessing their information after more details came to light last week, and will soon make a decision about whether to open an investigation.
Mr English said today that he told Mr Barclay while last year's investigation was under way that he should co-operate with police.
He said if the investigation was reopened Mr Barclay should agree to be interviewed.
"Yes, it would be my view he co-operates. I respect his legal rights to make his own decisions about how he's represented and what action he takes."
Mr English said he was reluctant to be drawn into detailed discussions about what happened, because of the possibility of a new investigation.
There have also been questions about whether a member of the National Party Board approached Ms Dickson to encourage her to drop her police complaint.
Mr English said he was unaware of those allegations.
"Whatever allegations are there I'm sure could be looked at by the party or police ... I would not be surprised in a national organisation when there was this employment dispute going on with the local party involved in it, that the national board took an interest.
"There may be different interpretations about what that amounted to, and if there are serious allegations then of course they should be dealt with by the appropriate authority."
Newsroom has revealed new allegations that several complaints were made by party members to the Board about Mr Barclay breaking party rules, but he was reselected anyway.
Mr English said he understood those matters had been "fully discussed in the context of his selection".
"And that was about the party rules, and that is all absolutely a matter for the party to deal with, the rules around selection."
He said the situation in the Clutha-Southland electorate "may have been mentioned" between himself and National Party President Peter Goodfellow.
Mr Goodfellow said he had "complete confidence" that directors would have acted "entirely appropriately" in any discussions they had with Ms Dickson, and said they would have talked to her about her options.