Moss Burmester, the former Olympic swimmer, has created fishing history after a tangle with a black marlin off the Northland coast on Sunday.
The 35-year-old Burmester - an avid free diver - is believed to be the first person to spear and land a black marlin in New Zealand waters.
But a disappointed Burmester cannot claim a record on a technicality, after landing the 163.4 fish in "a hell of a fight".
After firing the initial spear on target while diving at Cape Karikari, north-east of Kaitaia, he was handed two more guns by his boat mates who included spearfishing world record holders Nat Davey and Rochele Potter.
"I would love to be able to claim the record," Burmester said. "But it must be completely unassisted."
Burmester said the 15 minute fight involved scary moments, when rope tangled around his neck and feet. He accepted being handed the two subsequent spear guns for safety reasons, and to ensure the fish did not get away.
"Any fish which has been speared and gets away will almost always die," he said.
He described spearing as the most conservation-minded form of fishing, because individual fish were targeted for food which eliminated any by-catch.
"It was an epic, a huge thrill and something I've always dreamed of from an early age, to catch a marlin," he said.
"I just didn't ever realise it was possible or think that it would be through spearfishing. I got the same feeling and rush I had when I won my Commonwealth Games gold medal."
Burmester described the battle in graphic terms, saying: "I'm not sure why they are so rare...(but) Nat said they are one of the hardest fighting fish around.
"We think that my spine shot slowed it down. I had a go at finishing it off by swimming down, grabbing it by the bill in one hand, and stabbing my knife between its yes into its brain to kill it.
"However, it found a new lease of energy and went mental. I was holding on for grim death.
"Nat said I was getting lifted up out of the water and then slammed back down. It was like trying to hold onto a mechanical bull."
The Wild Bill fishing site describes the black marlin as "a most prized game fish because of its great fighting qualities and its bulky build."
"Black marlins are most regularly encountered around shallow reef structures. Catches of this species have dwindled in recent years, largely because of the swing towards lure fishing."
Burmester was fourth in the 200m butterfly at the 2008 Olympic Games in Beijing, won a short course world title and Commonwealth Games gold in 2006. The Auckland-based Burmester, who was raised in Tauranga, has entered the World Masters Games in Auckland next month.
People could listen in from 7pm via his official Facebook page.