The largest swordfish ever caught in Australia — and the second-largest in the world — may miss out on the official record because it did not meet strict rules in the way it was caught.

The monster fish was caught off Mallacoota near the NSW Victorian border on Sunday afternoon by a crew from the Ulladulla Game Fishing Club.

It weighed in at 436.2 kilograms, well above what is thought to be the current Australian record of 349kg for a swordfish, caught by a Melbourne man at the same location late last month.

The largest on record at 536.1kg was caught in Chile in 1953.

Ulladulla captain George Lirantzis said a fish that size usually dived deep when hooked, but this one stayed near the surface.

"As we got closer to it, it kept doing jumps and it was like someone was dropping missiles around the boat," he said.

"We had all these explosions with the fish coming up out of the water trying to obviously free itself."

'We don't go out to get trophies'

Mr Lirantzis said his crew had been targeting the emerging east coast swordfish fishery for the past three years.

"Last year we caught a fish that we all thought was going to be hard to beat," he said.

The 436.2kg swordfish after being reeled in by George Lirantzis and his crew. ( Facebook: George Lirantzis )

"It was 347 kilos and at the time was the biggest one in Australia.

"And a couple of weeks ago another one caught out of Lakes Entrance was 2 kilos heavier at 349 kilos."

But Mr Lirantzis said for him and his crew, fishing was not about competition or statistics.

"We don't fish for records and we don't do it for a certificate," he said.

"We do it because of our love for fishing and passion for the sport.

"We don't go out just to get a trophy, we do it to put fresh fish on our families' and friends' tables, and just so happened to get hooked up to the second-biggest fish of all time."

Record could prove harder to land

Having the fish caught and photographed is one thing, but getting it officially recognised by the Game Fishing Association of Australia (GFAA) is another.

The organisation has a long list of requirements, starting with the use of gaffs and nets, the way the fish is measured, and whether or not the anglers and their sea craft are properly recognised.

A swordfish caught off Mallacoota weighed in at 436kg, well above what is thought to be the current record. ( Facebook: George Lirantzis )

A GFAA spokesman would not comment on the specifics of the record until a claim had been lodged, but he was aware several recent significant catches in the area were attracting widespread attention.

For Chris Cleaver, who holds the title of Australia's lead tagger of swordfish, the catch shows not only how they are growing in popularity as a game fish in Australia, but how the catch can add to our current limited knowledge about them.

"We don't get many fish that size, not even from the long line commercial fishery," he said.

"So each new significant catch adds to that knowledge."

Most of the current knowledge about growth rates and spawning patterns comes from the northern hemisphere.

Ulladulla Game Fishing Club president George Lirantzis with a large yellow fin tuna. ( Facebook: George Lirantzis )

"It looks like Australia has a subspecies of swordfish which does have different growth rates," he said.

Mr Cleaver is a member of the Recreational Fishing Council of NSW, but his personal view is to support tag and release because he thinks it is more sustainable.

At the same time he dismisses critics who liken game fishing to stalking and hunting mammals in game parks.

"The animal isn't being stalked then shot, the animal is being hooked and then fought so the animal has a chance of escaping and a lot of them do," he said.