Todd Bakes, a member of the Game Fishing Club of Northern Tasmania, has recreationally fishing since childhood.

In late May this year the 49-year-old caught and tagged a 16kg southern bluefin tuna at Merricks Reef at St Helens Point - it was the only fish caught on his trip that day.

"I was the skipper so I wasn't actually planning on doing any fishing, but the boys twisted my arm," he said.

Earlier this month Mr Bakes and his crew cast their lines off the coast of Stanley and pulled in five bluefins, one of which was tagged.

At first, Mr Bakes did not think anything was unusual about the catch until he received a call from NSW Department of Primary Industries Fisheries Management Officer Clay Hilbert and was told to take a seat.

"Clay said that the tagged fish was originally caught on the East Coast, so I thought it was probably someone I knew," he said.

"Even when he told me it was my boat that caught it I still thought maybe it was one of my crew members, I couldn't believe it."

Mr Hilbert said that since the tagging program's inauguration in 1973 there had been more than 29,000 southern bluefin tuna tagged across Australia, 300 of which have been reported as recaptured, making the recapture rate roughly 1 per cent.

He said the odds of someone recapturing a fish that they had tagged themselves was far below that number.