Shane Jones lands a 305.9kg marlin

Shane Jones' blue marlin could be the biggest fish caught this year.

When Shane Jones headed out with some mates on a charter boat in the Bay of Islands, he wasn't expecting to land a 305.9kg blue marlin.

On Thursday Mr Jones, a former Labour MP and chairman of the Waitangi Fisheries Commission, and current ambassador for Pacific Economic Development, headed to a spot called the Queen's Buoy off Cape Brett.

El Donna skipper AJ Barton-Barry said it took Mr Jones just under an hour to bring in the behemoth, which was caught using a lure and a 37kg line.

And Mr Jones was pretty pleased with his catch.

"He was over the moon. He was a bit speechless.

"I don't think he expected to catch anything that big.

"That fish is up there with the biggest you'll get to see," Mr Barton-Barry said.

He even said he reckoned it could be the biggest fish caught in New Zealand so far this year.

And as for the blue marlin's fate, the skipper said it was taken to a local smokehouse, where it would be cured in kilogram pieces and vacuum packed.

"It's a beautiful fish, it'll last a couple of years," he said.