Smith's letter to the Human Rights Foundation has now given a new version from NZDF with the statement: "The 2010 raid in Baghlan involved a suspected civilian casualty."
It goes on to say that there was an investigation by two Afghan government ministries alongside the International Security Assistance Force but "NZDF does not hold a copy of the investigation".
Smith also said: "The NZDF has no reason to believe that the New Zealand personnel conducted themselves other than in accordance with the applicable rules of engagement."
The new detail came as Prime Minister Bill English met with Defence Minister Gerry Brownlee and Defence Force chief Lieutenant Colonel Tim Keating for a detailed briefing on claims against SAS actions in Afghanistan.
Today's meeting at the Beehive followed calls for an inquiry from the book's authors, Nicky Hager and Jon Stephenson, who said four of the six people were killed by US air support for the New Zealand troops.
The book also claimed the raid was a revenge attack on insurgents believed to be responsible for the death of SAS soldier Timothy O'Donnell, the first New Zealand combat death in Afghanistan.
The inquiry call has been supported by Labour, the Green Party, New Zealand First and United Future. Protesters also calling for an inquiry will hold a vigil on Parliament's grounds tomorrow morning.
English may decide some form of inquiry is needed, but that could be announced after the visit of Chinese Premier Li Keqiang, who arrived in New Zealand tonight and leaves tomorrow.
Labour leader Andrew Little said any inquiry needed to be headed by a high court judge or someone more senior.
"We need to know, for example, who was in command and control of the helicopter gunship that fired on the two villages causing most of the fatalities. We need to know the quality or the nature of the intelligence they had."
The raid was carried out with US air support and alongside Afghan troops New Zealand had been mentoring.
Wayne Mapp, who was Defence Minister at the time of the raid, said this week civilians were killed, and confirmed he had referred to the operation as a "fiasco".
In an interview with the Herald this week an SAS soldier said the two people found shot dead were killed by NZSAS marksmen who believed they were acting under "rules of engagement" governing actions on the battlefield.
He said the other four people killed died in a barrage of fire from United States aircraft called in by a New Zealander operating as the Joint Terminal Air Controller, who is responsible for directing air support.