A former soldier estimates there to be 100 NZDF personnel in Ukraine at any one time, though the true number would never be known.
File image. Photo: NZDF
The Defence Force said on 24 August it received reports a soldier, who was on unpaid leave, had been killed in Ukraine.
RNZ understands the man was soldier Dominic Abelen, who had been based at Burnham Military Camp and was killed while fighting in eastern Ukraine.
Former soldier Aaron Wood told Morning Report Abelen was "highly regarded as a soldier and man".
Most of the New Zealanders who went to Ukraine were trained and knew the risks, he said.
Wood is also the co-founder of volunteer veterans group, No Duff.
"In terms of the type of work that Dominic was doing, he was actually well trained to do that, the training they received through their court training, their trade training in the Royal New Zealand regiment prepares them for this - what we call open country conventional warfare.
"The actual experience of doing that under full noise combat conditions, well you can't replicate that during training and on exercise so there's only one way to find that out and as history shows, some people rise to the occasion, other people don't and that's just human nature.
"He'd been there for quite a while so he was well aware of what the risks were ... he was high regarded amongst his unit as well as back here in New Zealand, he had fought some significant contacts with the Russians up until this point."
There were a significant amount of New Zealanders in Ukraine for the size of our country, Wood said.
"There's layers of them so to speak, there's a relatively small amount on the frontlines fighting, a few tens at most, and then there is significantly more further back providing support and then there's the usual combat tourists who turn up taking selfies etc with long-dead Russian equipment.
"I would estimate no more than 100 [Defence personnel] at any one time, but it fluctuates."
It was highly likely there were a lot more there or who were going to arrive but we'd never know the true numbers, he said.
"I know for instance of a few [who are] very low profile, there's no mention of them on social media, you rarely ever hear from them in any other capacity except the odd headcheck so to speak, acknowledging that they're OK and they've been there for months."
The Russians were actively targeting Western fightings "and are hunting them" because they were highly prized for propaganda value, he said.
It was one of the main reasons people kept a low profile, he said.
"The smart ones don't want to stick their heads up too far.
"Certainly the Russians are looking to capitalise on their narrative and their agenda, which is neo-Nazis, Ukrainians are bad, Russians are good etc."
"I would estimate no more than 100 [Defence personnel] at any one time, but it fluctuates" - Former soldier Aaron Wood
In Eastern Ukraine, it was complete combined arms warfare like 1943 or 1945 on the Eastern Front, Wood said.
"Lot's of artillery, lots of armour, infantry, it's full noise warfare, the likes of which haven't been seen for generations after generations. Even though people like Dominic for instance experienced trained infantry, it's just the kind of job that they are trained for compared to your average Ukrainian.
"It's really really risky, high order warfare and as we saw from his reported circumstances of his death, that's traditional historical warfare taking trench lines, fighting off counter attacks."
Social media - open source intelligence - played a massive role in the war, Wood said.
"If you can imagine a bunch of amateur journalists running around, but armed and trying to figure out who's who in the zoo, where they are and what they're doing.
"You think about all the technology we have and how they can be hacked and people can find out where you are, metadata on photos etc. Both sides are playing that game and playing it hard."
Te Herenga Waka, Victoria University Wellington, foreign fighters and international law researcher Marnie Lloydd told Midday Report enlisting in another country's military was not currently prohibited by New Zealand law.
"Nor is it prohibited in general terms to join an armed group overseas," Lloydd said.
"New Zealand's actually always kept open the possibility of foreign enlistment, so in another state's forces and also certain types of foreign fighting."
Some forms of foreign fighting, like being a mercenary or joining a terrorist group were criminalised.
The soldier's death, while Lloydd gave her respects and condolences, gave pause for thought for whether more could have been done to deter or prohibit people fighting outside of official NZDF deployments, she said.
In general terms, many people had enlisted formally with Ukraine's foreign legion but she said "it seems that there are others who are acting more independently or have joined groups that don't necessarily come under the official military structures as well".
People also went to help in other ways like first aid, logistics or humanitarian assistance, she said.
"New Zealand's actually always kept open the possibility of foreign enlistment" - Foreign fighters and international law researcher Marnie Lloydd