A British angler – with a dozen helpers – has landed what could be the biggest freshwater fish ever caught with a rod and line, it emerged today.

The giant freshwater stingray, weighing as much as 350kg (772lbs, or about 55 stone), was the size of a garden shed and so cumbersome that Ian Welch had to enlist the aid of 12 other people to get it out of the water.

Welch, a professional fisherman, biologist and columnist for the magazine Angler's Mail, was visiting Thailand to help with a stingray tagging programme when he landed the monster in the Maeklong river. The 45-year-old said he was nearly pulled over the side of the boat when the specimen took his bait.

He said: "It dragged me across the boat and would have pulled me in had my colleague not grabbed my trousers – it was like the whole earth had just moved. I knew it was going to a big one.

"It buried itself on the bottom and the main fight was trying to get it off the floor. I tried with every ounce of power but it just would not budge. After half an hour my arms began shaking and after an hour my legs went. Another 30 minutes went by and then I put a glove on and physically pulled the line with gritted teeth and somehow I found the reserves to shift the fish."

Once the stingray was off the bottom, Welch, who weighs a relatively modest 73kg, managed to lift it to the surface relatively easily.

"As soon as we saw it there was just silence because everyone was just in awe of this thing," he said. "That line from the film Jaws came to mind about needing a bigger boat because we had to get it to the shore to tag it."

The group managed to put a large net under the fish and towed it to the bank. Welch, from Aldershot, Hampshire, said: "It took 13 people to lift it into a large paddling pool we had set up in order to tag it and take DNA samples.

"I was absolutely exhausted afterwards and did very little for the rest of the day and just had a cold beer. As a life-long angler and a biologist it is great that my two passions have come together and culminated in something I could only have dreamed of."

The female stingray was about 2 metres (7ft) long and the same width, and its tail measured about 3 metres (10ft). From its measurements it was calculated that it weighed at least 265kg, and possibly up to 350kg.

Its venomous barb had to be wrapped in cloth while it was out of the water. Once it was tagged the fish was released back into the river. Welch said he swam out with the fish and kissed it goodbye.

Angler's Mail has billed Welch's specimen as probably the largest freshwater fish fully authenticated as caught by rod and line.

A British angler – with a dozen helpers – has landed what could be the biggest freshwater fish ever caught with a rod and line, it emerged today.

The giant freshwater stingray, weighing as much as 350kg (772lbs, or about 55 stone), was the size of a garden shed and so cumbersome that Ian Welch had to enlist the aid of 12 other people to get it out of the water.

Welch, a professional fisherman, biologist and columnist for the magazine Angler's Mail, was visiting Thailand to help with a stingray tagging programme when he landed the monster in the Maeklong river. The 45-year-old said he was nearly pulled over the side of the boat when the specimen took his bait.

He said: "It dragged me across the boat and would have pulled me in had my colleague not grabbed my trousers – it was like the whole earth had just moved. I knew it was going to a big one.

"It buried itself on the bottom and the main fight was trying to get it off the floor. I tried with every ounce of power but it just would not budge. After half an hour my arms began shaking and after an hour my legs went. Another 30 minutes went by and then I put a glove on and physically pulled the line with gritted teeth and somehow I found the reserves to shift the fish."

Once the stingray was off the bottom, Welch, who weighs a relatively modest 73kg, managed to lift it to the surface relatively easily.

"As soon as we saw it there was just silence because everyone was just in awe of this thing," he said. "That line from the film Jaws came to mind about needing a bigger boat because we had to get it to the shore to tag it."

The group managed to put a large net under the fish and towed it to the bank. Welch, from Aldershot, Hampshire, said: "It took 13 people to lift it into a large paddling pool we had set up in order to tag it and take DNA samples.

"I was absolutely exhausted afterwards and did very little for the rest of the day and just had a cold beer. As a life-long angler and a biologist it is great that my two passions have come together and culminated in something I could only have dreamed of."

The female stingray was about 2 metres (7ft) long and the same width, and its tail measured about 3 metres (10ft). From its measurements it was calculated that it weighed at least 265kg, and possibly up to 350kg.

Its venomous barb had to be wrapped in cloth while it was out of the water. Once it was tagged the fish was released back into the river. Welch said he swam out with the fish and kissed it goodbye.

Angler's Mail has billed Welch's specimen as probably the largest freshwater fish fully authenticated as caught by rod and line.

A British angler – with a dozen helpers – has landed what could be the biggest freshwater fish ever caught with a rod and line, it emerged today.

The giant freshwater stingray, weighing as much as 350kg (772lbs, or about 55 stone), was the size of a garden shed and so cumbersome that Ian Welch had to enlist the aid of 12 other people to get it out of the water.

Welch, a professional fisherman, biologist and columnist for the magazine Angler's Mail, was visiting Thailand to help with a stingray tagging programme when he landed the monster in the Maeklong river. The 45-year-old said he was nearly pulled over the side of the boat when the specimen took his bait.

He said: "It dragged me across the boat and would have pulled me in had my colleague not grabbed my trousers – it was like the whole earth had just moved. I knew it was going to a big one.

"It buried itself on the bottom and the main fight was trying to get it off the floor. I tried with every ounce of power but it just would not budge. After half an hour my arms began shaking and after an hour my legs went. Another 30 minutes went by and then I put a glove on and physically pulled the line with gritted teeth and somehow I found the reserves to shift the fish."

Once the stingray was off the bottom, Welch, who weighs a relatively modest 73kg, managed to lift it to the surface relatively easily.

"As soon as we saw it there was just silence because everyone was just in awe of this thing," he said. "That line from the film Jaws came to mind about needing a bigger boat because we had to get it to the shore to tag it."

The group managed to put a large net under the fish and towed it to the bank. Welch, from Aldershot, Hampshire, said: "It took 13 people to lift it into a large paddling pool we had set up in order to tag it and take DNA samples.

"I was absolutely exhausted afterwards and did very little for the rest of the day and just had a cold beer. As a life-long angler and a biologist it is great that my two passions have come together and culminated in something I could only have dreamed of."

The female stingray was about 2 metres (7ft) long and the same width, and its tail measured about 3 metres (10ft). From its measurements it was calculated that it weighed at least 265kg, and possibly up to 350kg.

Its venomous barb had to be wrapped in cloth while it was out of the water. Once it was tagged the fish was released back into the river. Welch said he swam out with the fish and kissed it goodbye.

Angler's Mail has billed Welch's specimen as probably the largest freshwater fish fully authenticated as caught by rod and line.

• http://www.guardian.co.uk/world/2009/feb/24/stingray-catch-thailand-fishing