Prime Minister Bill English has told Morning Report he is "not completely ruling out" an inquiry into claims New Zealand soldiers were involved in raids in Afghanistan in which civilians died.
However he said allegations of war crimes appear to be unfounded, and there was unlikely to be an inquiry into that aspect.
A new book - Hit & Run, by investigative journalists Jon Stephenson and Nicky Hager - claims six civilians died and 15 were wounded in raids in 2010 directed by the New Zealand SAS which also involved American helicopter gunships and Afghan forces.
At the book's release, Stephenson and Hager said they were not specifically claiming war crimes had been committed, as that was a highly technical legal term and they would leave experts to examine whether that was the case.
The Defence Force had admitted in an Official Information Act release a week before the book was published that there was a "suspected civilian casualty" in a 2010 raid in Baghlan Province.
However, last night the NZDF released a statement accusing Hit & Run of "major inaccuracies" and said the central premise of the book was "incorrect".
Mr English has previously said he is 100 percent behind the Defence Force.
This morning, he said it was a complicated situation.
"There's been so much discussion about this, so many kind of layers of sources and allegations that I think any statement made outside the scope of the original investigation is one you'd need to look into pretty carefully.
"If it's the case - as it appears to be - that all the allegations relate to different villages than where the New Zealand operation actually occurred that does tend to undermine a lot of the allegations.
However, any new information that came out would be welcome.
"If there was... other evidence that came forward, now, of course we'd be interested in that."
He said the comments by the Defence Minister at the time Wayne Mapp that the operation was a fiasco were based on a documentary which was produced by author Stephenson.
War crime allegations require police investigation, not inquiry
However, while Mr English seemed clear there was unlikely to be a war crimes inquiry, Wellington lawyer Graeme Edgeler said the nature of the allegations made this a case for police.
"Inquiries - you know, a commission of inquiry or a government inquiry of some sort - can't look at criminal action, can't look at whether there's civil liability," he said.
"At least some of these are allegations of war crimes" - Wellington lawyer Graeme Edgeler
"There are one or two very clear allegations of war crimes in the book, the one I think the strongest being that 10 days after the raid there was a second raid, the purpose of which was solely to blow up civilians' houses.
"There was no action, no need to fire guns or anything, it wasn't defensive it was 'we are going somewhere to blow up civilians' houses' ... and in war, that's recognised as a war crime."
"That's not something that a government inquiry should be looking at, that's something the police or the military police should be looking at."
However, he also said wider questions of New Zealand's activity in Afghanistan could benefit from an inquiry.
Hager rejects Defence Force version of events
Hager said the investigative journalists were genuinely shocked and confused by what the Defence Force was saying.
"For their version of events to be correct, there would have to be two identical raids with identical forces and identical helicopters and identical targets - at the same time - 2km away from each other along a valley, which is completely ridiculous."
Lt-Gen Keating's statement yesterday said that New Zealand troops were never involved in operations in the two Afghan villages, Naik and Khak Khuday Dad, named in the book.
The statement said the authors appeared to have confused interviews, stories and anecdotes from locals with Operation Burnham, 2km to the south, which focussed on a town called Tirgiran.
It said the villages in the book and Tirgiran were separated by mountainous and difficult terrain.
"The ISAF investigation determined that a gun sight malfunction on a coalition helicopter resulted in several rounds falling short, missing the intended target and instead striking two buildings.
"This investigation concluded that this may have resulted in civilian causalities but no evidence of this was established," Lt-Gen Keating said.
But Hager told Morning Report today there was no way there were two operations in the area at the same time with the same name.
"What we've got in the book is that we have got SAS people describing a raid that they did in different towns, they named particular people's houses that they went into, searched, attacked, burnt down.
"I find it completely staggering that after five days this is what they have come up with becuase it is completely lacking in credibility" - Hit & Run co-author Nicky Hager
"We've got the villagers talking about exactly the same named people's houses in these two villages, we've got people talking about the bodies they found and the injuries, we've got the Minister of Defence of the time coming out and saying 'yes, I agree, it was a disaster and a fiasco and innocent people died.
"And most important of all, in the book we've got the people who were involved in this, the New Zealand secret staff telling us the name of this operation was Operation Burnham.
"And the first time the world knew about that name was when they read it in our book, that the operation which involved civilian deaths was called Operation Burnham.
"Now, the statement which Defence has just put out claiming that actually 'no, no, no, we were just 2 km away,' they're also calling it operation Burnham and there wasn't two Operation Burnhams in those mountains on the same night."
"It seems to me they are acting recklessly in their desperation to try to find a way to not take responsibility."
He said they had interviews with SAS people, but unfortunately they did not keep records of the maps that were used, which he said would have made it clear the area that was involved in the operation.
He said that last night he and Stephenson had called a doctor from the area.
"And [we] said, 'they're saying there's another village by the name of Tirgiran where they did their raid - has that place been raided, was it raided at that time?'
"And the doctor said 'no, there was one raid, it was the one at Naik and Khak Khuday Dad.
"So we tried to figure out what they were talking about but none of it makes sense.
He said what needed to be done to establish all the facts was a to hold a full inquiry.
'They've denied for years, now they're admitting it'
Peter Hosking from the Human Rights Foundation backed up Hager, saying information he received from the Defence Force under the Official Information Act contradicted the Defence Force version of events.
"The response that we got was that there was a suspected civilian casualty in the 2010 raid in Baghlan. I'm confident it's the same raid that was talked about in the book, I have no idea what the defence force is talking about with this other raid."
"It all seems to me to be obsfucation. They're just trying to pull a confusing veil over what's happened" - Peter Hosking from the Human Rights Foundation
"The statement's still on their website, referrring to the ISAF investigation and saying it's concluded that the allegations of civilian casualties were unfounded. So what we're saying is they've denied for years, and now they're admitting it."