An extraordinary moment purportedly showing a New Zealand volunteer fighter storming a Russian position and being recognised by a Ukrainian prisoner has been revealed.

Former NZ Army soldier Kane Te Tai has been fighting with an International Legion unit on the frontline of Ukraine’s war with Russia under the codename ‘Turtle’.

Te Tai left New Zealand to join the foreign brigade after Russia’s invasion last year – and was reportedly alongside another Kiwi soldier, 28-year-old Dominic Abelen, who was shot dead trying to re-take an enemy trench last August while on unpaid leave from the NZDF.

Now, a video has emerged of Te Tai appearing to show him saving a Ukrainian friend’s life during a raid on a Russian bunker and basement.

It shows armed troops entering a dark underground room, after coming down stairs littered with rubble debris, and a New Zealand-accented voice shouting, “Hands up!”.

“Give me your hands, show me your hands,” the voice says in footage posted to Te Tai’s Instagram account and which has been widely shared on other social media channels.

Te Tai writes he had been sceptical of a voice saying “Ya Ukrayinets!” (I’m Ukrainian) but “stopped the lads from tossing a grenade in”.

A man in battle fatigues is seen lying face down on the ground. He is told to turn over while is searched and appears to recognise Te Tai, exclaiming, “New Zealand! New Zealand!”

The Kiwi voice replies, “My brother! I know him, I know him.”

“I recognised him,” he writes.

“It was my friend who I thought was killed by the Russians when they invaded his house.”

Dominic Abelen, from the Royal NZ Infantry Regiment's 2/1 Battalion, was killed in Ukraine. Photo / Facebook

Te Tai says the man had been “heavily starved” for two months and “forced to drink anti-freeze for entertainment”.

“He barely looked like the man I knew a couple of months ago,” he says.

“But it was the best thing to happen to me in this God-forsaken war.

“To be able to save your friends is something that almost never happens but I’m thankful and feel blessed that it was us that could pull him from that hell hole.”

New details emerged of Abelen’s death last month after an embedded journalist wrote his account of what happened.

Reporter Luke Mogelson had just joined the unit in a town close to Pavlika, a frontline village about 80km north of Mariupol, when he heard about a friendly fire incident that the foreigners had with the Ukrainian 72nd Mechanised Brigade - to which they were officially attached - just before Abelen’s death.

The International Legion team were moving to secure a tactically important tree line where earlier drone surveillance had shown Russian soldiers occupying a trench system.

They embarked on the mission late in the evening and although they had briefed the 72nd of their route, a Ukrainian unit opened fire on them as they approached.

The team shot back.

“We won, they didn’t,” said Te Tai was said to be the unit’s leader under the codename ‘Turtle’.

“Until then, we’d been lucky. And our luck ran out that night.”