County mammal recorder (sweet job), Dr David Leech, has declared the sighting by a group of bird watchers “highly reliable,” after Giles Dunmore, one of those in the group, revealed he had seen several killer whales off the coasts of Tenerife and Alaska.

Mr Dunmore and his friend Phil Vines were watching sea birds last Thursday morning when they spotted the whale.

“It was a long way out, but I could see it was a big cetacea. I yelled out to Phil ‘I’m certain it’s an orca’,” said Mr Dunmore, who has been a twitcher in Norfolk for 57 years. 

Their sketches will be passed to the Norfolk Biological Information Service who will confirm the genus of the whale.

Dr Leech said killer whales “do have quite a distinctive dorsal fin”.

“With that and the experience of the observer and knowing that they had good optical kit, because they were using telescopes to watch the birds, I think in combination that sounds like a really quite a reliable source.”

However Dr Leech also said the likelihood of there being a pod of whale frequenting the waters off the English coast are slim, as whales prefer much deeper waters.

He speculated that it may have been food sources which drew the whale off course.

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