New Zealand will not hold an inquiry into "discredited" allegations its special forces committed war crimes in Afghanistan, Prime Minister Bill English said on Monday.
A book published last month alleged the SAS staged a "revenge attack" in 2010 after the death of a New Zealand soldier, but faulty intelligence meant they killed six civilians including a three-year-old girl.
"Hit and Run", by investigative journalists Nicky Hager and Jon Stephenson, also claimed the military and government covered up the raid's failure, falsely saying nine insurgents had died.
Rights groups including Amnesty and Transparency International have called for an independent investigation of the allegations.
But English said Chief of Defence Force Lieutenant General Tim Keating had looked into the book's claims and found no evidence of wrongdoing.
"He's come to the conclusion that (there was) no evidence of misconduct by the troops and no evidence of war crimes. We accept that conclusion," English told reporters.
He insisted Keating's inquiries were independent because the military chief was not personally involved in the raid.
English said he had personally viewed edited video footage of the raid and it showed the troops followed the rules of engagement.
He said the classified footage would not be released and refused to discuss its contents.
"I'm satisfied that we can trust the Defence Force process and trust the chief of defence forces," he added.
Allegations 'lack substance'
English said New Zealand's SAS was renowned as one of the best special forces units in the world.
"The only question mark over their name is a series of allegations of war crimes in a book which has been discredited," he said.
"We're not bound to hold an inquiry simply because someone makes allegations, particularly when those allegations turn out to lack substance."
New Zealand sent a reconstruction team and a small special forces contingent to join the NATO-led operation in Afghanistan in 2003.
In early August 2010, Lieutenant Tim O'Donnell became the first of New Zealand's 10 military deaths in Afghanistan when his patrol was hit by a roadside bomb.
The SAS raid in the northern province of Baghlan, carried out with US helicopter support, took place about two weeks later on August 22.
In the following days Mohammad Ismail, a district chief for Tala Wa Barfak, where the incident occurred, told AFP that eight people died in the raid, all civilians.
The New Zealand military initially kept silent about its involvement, then said nine insurgents were killed and no civilians harmed.
English on Monday said it was possible the raid resulted in some civilian casualties but such allegations were "speculation" with no evidence backing them up.
The military has stood by its figure of nine insurgent deaths and says the raid it conducted was carried out several kilometres from the area detailed in the book.
Co-author Hager has rejected the assertion and accused the government of perpetrating a cover up by allowing the military to investigate itself.
"It's actually asking the people who are trying to hide it and protect their reputations to make the decision, and that's never going to work out right," he told TVNZ.