Operation Burnham inquiry: Top military official says possible civilian casualties were due to mechanical gun fault

A top military official has recalled feeling "relieved" at a report into the actions of the New Zealand Defence Force (NZDF) in Afghanistan in 2010.

Colonel Rian McKinstry says he learned from an International Security Assistance Force (ISAF) report, that possible civilian casualties were due to a mechanical gun fault, not New Zealand troops.

At the Operation Burnham inquiry hearing on Tuesday morning, Colonel McKinstry said he was told CivCas (civilian casualties) would have been collateral and unintentional. 

Further questions will be raised on Tuesday, about a critical report into Operation Burnham. 

An inquiry into allegations of civilian deaths during a 2010 SAS-led raid in Afghanistan, heard on Monday an ISAF document miraculously appeared in a Defence Force safe, when a staffer gathered a bundle of documents ahead of a Native Affairs report, in 2014.

But who put it there remains a mystery, as it contains details pointing to the possibility of casualties, due to a faulty gun sight on a US helicopter. 

The question caused tense scenes during the cross-examining of military brass on Monday.

Former Chief of Staff, Commodore Ross Smith, stammered as he was grilled about the document and its 2014 discovery.

The ISAF document has been classified by NATO, and its documents could not be disclosed.

NZDF says there was no cover-up as they were unaware they had the report but admits a series of "missteps". 

Commodore Smith said then-defence Minister Jonathan Coleman was "not happy" about the document going unnoticed.

However, nothing came to light, even following a search through the database, meaning the investigation was closed and the document remained a mystery.

There were tense scenes when counsel for Hit and Run co-author Jon Stephenson, Davey Salmon, argued why the Defence Force did not refer to the document's findings in response to the book's release.

But Smith claims he was in a rush to get out a statement, and that at the time he is unsure whether he thought the two (the book and ISAF report) were actually related.

"We did not refer to it when we put this press release together," Commodore Smith said.

The NZDF narrative remained that reports of civilians deaths were unfounded.

Sir Jerry Mateparae said he had been informed that the ISAF findings ruled out civilian deaths, however, it later emerged the staffer who informed him of this was only allowed to read a single paragraph of the report.

He was also unable to answer why press releases by the investigation team, which mentioned the possibility of civilian deaths, were not included in briefings given to then-Defence Minister Wayne Mapp.

He admitted information given to Mapp, and then-Prime Minister, John Key, was "clearly wrong".

The inquiry is continuing.

Newshub.