UnitedFuture leader Peter Dunne says some sort of inquiry is needed into the Afghanistan raid because there's too many unanswered questions.

Without an inquiry into alleged civilian deaths in a raid involving elite Kiwi troops there's no stopping speculation, including a possible cover-up by the New Zealand Defence Force for the actions of American soldiers, says Peter Dunne.

The United Future leader and Minister of Internal Affairs says in the "absence of a clearer disclosure as to what actually happened you're left with all sorts of interesting possibilities".

Authors Nicky Hager and Jon Stephenson, in their recently released book Hit and Run, alleged SAS troops were involved in raids on two villages in Afghanistan in 2010 that left six civilians dead, including a three-year-old girl.

ROSS SETFORD/NZPA Former Defence Minister Wayne Mapp says a full independent inquiry into SAS raids in 2010 is probably not needed.

NZDF Chief of Defence Lieutenant General Tim Keating has strongly denied the allegations and on Wednesday Hager and Stephenson conceded the location of the villages in their book was wrong, but while the NZDF had the right location, they had the wrong villages.

READ MORE:

* Hit and Run authors concede they got a location wrong

* Villagers engage NZ lawyers over SAS raid

* As it happened: NZDF condemns book allegations

* Bill English says SAS inquiry unlikely

On Thursday NZDF released a new document directly comparing where Operation Burnham took place to where the authors claimed it took place in the book.

RNZ Lieutenant General Tim Keating has acknowledged there may have been multiple civilian casualties during Operation Burnham, which was carried out following the death of Lieutenant Tim O'Donnell who was killed when insurgents attacked his patrol.

Dunne said the unanswered questions are precisely why a specific inquiry was needed to determine the facts.

"Is it possible, when Keating says 'I've seen the video, I know what happened and New Zealanders weren't involved', that he's also seen some other things on the video that he doesn't want to acknowledge, because they could be rather delicate in terms of our relations with the Americans, for example.

"Now I've got no evidence to suggest that's the case but my point really was that in the absence of a clear explanation of what actually happened, you're left open to all these possibilities," he said.

If it was a cover-up for the Americans you could understand the motive, Dunne says, as it "wouldn't be in New Zealand's interests at the moment to rock the boat by dropping the United States in it".

Dunne said the government's backing away from an inquiry - on Wednesday the Prime Minister said there was still no "credible evidence" that civilians were killed - is starting to look like they're hoping "public interest will wane".

"I don't think that's good enough. I don't think on the other hand that just because Nicky Hager's made some allegations they need to be automatically investigated but there is enough in this story ... to make you think that it warrants some further examination."

The SAS's reputation is "enviable" for being "highly skilled and professional" and needs to be protected, he said.

"I just think (NZDF) trying to shut up shop and pretend this is all a non-event doesn't help that reputation - it potentially detracts from it.

"At the moment you're left with this bigger question of something happened, we don't know what it was and on the face of it it doesn't look good."

WAYNE MAPP SAYS FULL INQUIRY NOT NEEDED

Former Defence Minister Wayne Mapp, who was in Afghanistan at the time of the raid, in a post on Pundit has said both Kiwi soldiers and Afghanis can be "honoured" by finding out what happened the night of the August raid - but a full inquiry may not be needed.

"In August 2010 when Operation Burnham took place I was in Afghanistan on a visit arranged months before. I understood that the operation was among the most significant operations that New Zealand had undertaken in Afghanistan.

"I had been fully briefed on the plan on the morning before it took place. Based on the briefing, and on the advice of the military professionals, I recommended that it proceed," he wrote in a post on Pundit.

While Mapp says he has no doubt the SAS acted to the highest ethical standards, he also knew knew that the operation had not achieved its stated aims of arresting or otherwise dealing with the people targeted.

"For me, it is not enough to say there might have been civilian casualties. As a nation we owe it to ourselves to find out, to the extent reasonably possible, if civilian casualties did occur, and if they did, to properly acknowledge that."

But Mapp says that doesn't "necessarily require an independent inquiry".

"In fact we are most likely to get this sort of information through diplomatic approaches to the Afghan government, and trusted NGO's on the ground," he said.