The gigantic flat fish, which was 8ft wide and 14ft long, took nearly two hours to reel in.

It was caught by American TV nature conservationist Jeff Corwin on the Mae Klong river in Thailand earlier this week. 

It was so big that several men on board a small fishing boat had to take it in turns to help on the rod. 

After getting the ray alongside the boat it was pulled into a specially-prepared pen where seven people lifted it out of the water so it could be properly measured.

Specialists measured its width, length and girth to calculate its weight.

The epic catch will be featured on 'Ocean Mysteries with Jeff Corwin', which will be broadcast on ABC in the US later this year.

After the catch Mr Corwin tweeted: 'Potential world record freshwater fish, giant stingray, 14ft X 8ft! in Thailand filming for ABC's Ocean Mysteries.'

He added: 'According to National Geographic, Fishsiam and Dr Nantarika Chansue, a leading stingray expert, this is likely to be the largest freshwater fish ever caught with a rod and reel.

'The battle to bring this giant fish to the boat was epic and it took many hours and multiple guys rotating off and on the reel.

'The experience was a true highlight of the series, not only connecting with a record-sized ray but being a part of cutting edge science.'

Rick Humphries, of UK company Fishsiam, whose fishing guides helped reel in the ray, said: 'We have caught over 450 different stingrays and our estimations have been proved highly accurate on the rare occasions we have weighed this species.

'The larger specimens are always female and quite often pregnant, as was the case with this capture.

'The latest capture indicates that these stingrays are growing at a fast and healthy rate.'

It is thought the previous record was held by British angler Ian Welch, who landed a giant stingray weighing between 590lbs and 770lbs in the same river in 2009.

The Guinness Book of World Records lists the Mekong giant catfish, weighing up to 660lbs, as the 'world's largest freshwater fish'.

(dailymail.co.uk)