An endangered fish made a rare appearance in South West waters – only to be speared by a diver.
Brett Morison caught the northern bluefin tuna while underwater fishing in Portland Harbour, Dorset.
His 35lb catch has been confirmed as a national record by the British Spearfishing Association, which has no log of any tuna being caught in UK seas.
The species is rated "critically endangered" after years of over-fishing and conservationists have warned it should be left alone.
Richard Harrington of the Marine Conservation Society said: "Bluefin tuna are at the point of extinction, and it would be irresponsible to encourage anglers and fishermen to target them."
The northern bluefin is usually found in warmer waters in the Atlantic and Mediterranean, but is thought to be moving north due to global warming extending its feeding grounds.
Mr Morison, 37, of Newquay, said he had made the trip to Portland with friends James Keith and Scott Bartecki to take part in an annual spear-fishing competition, only to find it had been cancelled due to poor weather but they went into the murky waters undeterred.
Just minutes later, he got the shock of his life when a large fish sped out of the gloom towards him just six metres below the surface.
"It sounds a bit crazy but I immediately thought, 'that's a big mullet.' By this time it was turning hard and fast after an arc from right to left, and I thought 'Oh my God, it's a tuna."
He quickly fired his spear and skewered it at almost point blank range as it raced past – only later learning that it was a rare bluefin tuna.