A monster ocean sunfish has washed up on a north Norfolk beach, thousands of miles from its home territory.

The fish, which usually lives in tropical and temperate waters, was discovered dead on Overstrand beach yesterday morning.

Carl Chapman, regional co-ordinator for marine conservation body the Sea Watch Foundation, was alerted at about 10am by a man walking the beach with his children.

'They are the heaviest bony fish in the world. This one must have weighed at least a couple of hundred weight - it was like lifting bags of cement,' said Mr Chapman, who is based in Northrepps, near Cromer, and runs wildlife tours.

'I suppose from fin tip to fin tip it measured about six foot. Both eyes were still intact and were the most beautiful blue. The surface of the fish was just like coarse sandpaper. They're glowing silver when they're alive, hence the name, but I think this one must have died a few days earlier. It was a sandy colour.'

Mr Chapman said he had seen ocean sunfish before, off the Scilly Isles and in the Bay of Biscay, but never this far north.

He speculated that it had possibly been swept up by the Gulf Stream and into the North Atlantic where it had perhaps been trying to re-orientate itself.

Sunfish had a dorsal and a ventral fin but no tail, according to Mr Chapman. They moved by beating their fins and fed mainly on jellyfish.

He returned to the beach this morning but said very rough seas had taken the corpse away.

Mr Chapman added: 'It was a thrill to see one locally. They don't often appear.'