Investigative writer Nicky Hager says sources from the Defence Force have exposed a culture of bullying, sexual violence, drinking and cover-ups in the military.
In Mr Hager's 12-page investigation, published in the North & South magazine today, he details how a source revealed that an SAS soldier - known as Corporal B for privacy reasons - was awarded the second-highest military honour despite previously being considered for court-martial action for killing two children in Afghanistan.
"The Americans asked the SAS commander if they could take one of the New Zealand medical staff, a medic, on a raid they were doing on a Afghanistan compound," said Mr Hager.
Medics fall under a protected status in war battles and strict rules are imposed on them under the Geneva Convention, he said.
"Specifically, a medic can only ever shoot in self-defence or to protect wounded people under their care. These are very important and long-standing rules of war," Mr Hager's report stated.
"But they can't defend the American forces around them or something, and that's where it all went wrong," he told Morning Report.
Mr Hager said the soldier got involved in a firefight and later found he had shot two young boys, who joined the adults in defending the compound.
"[Corporal B] saw that the people he had shot were just little boys that [they were] some boys 12 or 13 [years old], the same age as his children."
He said the Americans suggested Corporal B should get a medal for his assistance, but when he returned to base, the soldier was told he could be court-martialled.
"So he was thinking 'oh no, I've killed children', and the Americans were saying 'great work man, you helped protect us, we might give you a medal'.
"And then when he got back to base he became a very unhappy and confused person, because the SAS commander was saying 'well hang on a moment, you've broken all the rules here, we're gonna court-martial you'.
"There was this man who was upset about hurting children, was angry at the military for sending him into a situation where it could happen like that with the American forces, and he was incredibly disillusioned because they were going to charge him for... having broken international law."
However, the Defence Force said it did not consider court-martialling Corporal B. Mr Hager said the Defence Force also did not confirm the source's story on Corporal B either.
Mr Hager said no such trial took place and Corporal B was eventually awarded a New Zealand Gallantry Decoration.
"It was also the same period where the Willie Apiata raid had happened and they were getting ready to give him a VC and they decided exactly the same thing with this soldier.
"They forgot that he had done things wrong, they actually covered up the whole thing and didn't do any investigations into the war crimes side of it, the Geneva convention side."
Mr Hager's investigation states Corporal B had left the SAS and NZDF by the time of the award.
Claims of 'dry theatre of operations' breach
Military members who went to Afghanistan operated under "dry theatre of operations" - a strict ban on alcohol in war areas - in the early stages of war.
Mr Hager said some of the NZDF members respected those rules, however, the SAS ignored the ban.
"This is an example of how there's a culture of the rules that apply to other people that don't really have to apply to them [SAS] and they'll keep it secret," Mr Hager said.
"What I was told, again by this SAS man who was there during it, was that the troops around them, and even the American troops, didn't have alcohol."
Instead: "When supplies were flown from New Zealand on large pallets, the outer layer of the pallets would be boxes of ration packs, made up by a firm at Linton. But most of the load, hidden inside the ration packs, the source says, was 'beer, spirits, everything. You name it, it was in there. The [SAS] unit organised it all'," the report detailed.
"They'd have huge screaming wonderful parties from their point of view and they'd invite the other nations to come along to them but they were totally breaking the rules," Mr Hager told Morning Report.
The NZDF told North & South "small quantities of NZSAS-branded wine and spirits, brought and paid for privately by Papakura Camp Mess members, were taken into Afghanistan for consumption and used as gifts for coalition partners and friends".
Claims sexual assault ignored
The same year NZDF released a report on sexual abuse in the Royal New Zealand Air Force, Mr Hager said, a woman came forward to report a complaint on sexual assault.
"This is a story [that took place] in Ohakea three years ago, in 2015, where a woman who was a civilian worker there went to a Friday night party of the staff who she worked with and two of the other men there on the air force base decided they'd get her," he said.
"One came up in front of her and grabbed her by the breast while the other one shoved himself behind her and they pinned her between them, in a way which they thought was a hoot and she felt really terrible and was very unhappy about."
However, her seniors did not take her complaint seriously, Mr Hager said.
"She did exactly what the military says that people should do in its documents... she went to her boss and said 'I'm laying a formal complaint about this, I'm not happy with what happened' and he just shrugged it off and so she went to her boss' boss at Ohakea and said 'this has happened to me, I want you to take some action, I'm not happy with what's been done to me' and again she got shrugged off."
The woman pursued the matter but still was getting pushed off, Mr Hager said.
"She went to the defence force lawyers, she went to the deputy chief of the air force, and then she went up to the chief of the air force - and at every level they said 'no' and the reason they were saying no, according to the people who knew about it who were involved, was because the two men who had done it to her were part of an at-risk trade group.
"They didn't want something to happen to them, like to be fired for what they had done, because it was hard to get those particular skills.
"The final thing is that when she couldn't even get the chief of the air force to do anything about it, the defence lawyers on her behalf took it to the chief of staff, Tim Keating, and he refused to act as well."
An NZDF spokesperson told North & South appropriate action had been taken "in accordance with the established policies and procedures in place at the time". No further comment would be made "because to do so may breach the complainant's privacy".
Mr Hager, along with John Stephenson, wrote the Hit & Run book which claims six civilians were killed and 15 injured in a raid on two Afghan villages by the elite New Zealand soldiers.