Thousands of social media users have followed an epic 19-hour battle on the water between a crew of fishermen and a "record tuna".

Just before 7:00pm on Monday a member of a Tasmanian team of professional game fishermen posted an update to Facebook on the tug-of-war.

Thousands of people commented on the battle and the post was shared by hundreds around the world.

Crew member Adrian Morrisby said the crew were looking for big fish but the one they hooked was bigger than they expected.

"These fish that we were hunting were jumbo sized tuna, so 100 to 200 [kilograms]," he said.

"We got one on [the hook] at about 11:30am yesterday [Monday] which, normally, after an hour or two you've got them tagged or ready to weigh.

"Anyway this fish went on through the night and into the next day."

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Mr Morrisby said he was out of range for posting pictures online so he relayed updates through a friend onshore who then posted them to Facebook.

"I had a lot of friends [interested], I had to let them know how I was going," he said.

"They were sending me messages and I was replying with what was going on and they started updating the Facebook page for Team Penn International."

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Those updates started to get shared by dozens of Facebook users and eventually thousands of people from around the world were following the fight off the coast of Tasmania.

"I was getting the reports back and it had me in tears there a couple of times from the support we were getting, it was amazing," Mr Morrisby said.

Users like Tracey-Lee Kleeman from Hobart posted messages of support.

"Hold in there everyone u can do it u have come so far, and just think when u get it in the boat u can all have a good drink and rest stay strong (sic)," she wrote.

Adam Dziewierz from the Gold Coast also threw his support behind the team, saying: "Good luck guys, ex-Tassie boys in Queensland are cheering for you guys as well."

The fishermen said they got a few "good looks" at the fish before it eventually broke the line and got away.

And Mr Morrisby said there were some passengers on board who knew what they were talking about.

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"We reckon it was around about 200 kilos, we like to underestimate rather than over," he said.

"The current Tasmanian record, I think is about 167 kilograms.

"We had the president of the Game Fishing Association of Australia whose boat we were on, Brett Cleary, and the NSW game fishing president was there as well.

"They know their stuff pretty well as you can imagine."

The crew had to take turns trying to reel the monster fish in as it dragged the boat more than 40 kilometres before freeing itself.

"It dragged us right out to the continental shelf and down below Tasman Island to Port Arthur in the end," Mr Morrisby said.

But the battle ended just before 7:00am when a freak accident allowed the fish to get away.

Onshore team member Josh Cumberland broke the news to the online following.

"Well everyone that is that, absolute drama, after 19.5hrs of fishing, an albatross has hit the line where the double meets the wind on! and fish gone (sic)," he wrote.

Fisherman Kelly Hunt in shock after a freak accident ends a 19-hour battle with a "record" tuna. ( Facebook/ Team Penn International )

The news that the fish had won was greeted with more supportive messages.

"Absolutely gutted! Can't imagine how they feel! Amazing effort!" wrote Cheyne Ramsay from Kiama, NSW.

Hobart man Justin Causby drew on his own personal experience to relate the loss.

"I don't think I've felt so empty since I got knocked back on my wedding night," he wrote.

"Hard luck but that's fishing. Amazing effort from all."

After a huge night's work ended in failure Mr Morrisby was philosophical about the outcome.

"He deserved it," he said.

"He fought a good battle and he won and that's part of fishing and we were quite happy that he won.

"To fishermen it was the battle of all battles, once you go over a couple of hours it's an epic battle you don't see that anywhere in the world much."

But all was not lost, with the fishing team's Facebook page picking up thousands of new followers ready for the next offshore battle to play out online.