A naturalist who saw a whale while volunteering on a nature reserve said it was 'the size of a small fishing boat'.

Trevor Williams was working at the Norfolk Wildlife Trust's reserve at Cley when the creature surfaced 1,500m off shore on Monday morning.

"Unfortunately I only got a very brief view as it breached," he said. "I just got to see its long grey back, the size of a small fishing boat, and dorsal fin before it dived again."

Mr Williams said he reported the sighting to Norfolk whale expert Carl Chapman, who runs a blog on cetaceans seen around the county's shores.

"I phoned a couple of people - including Carl Chapman - and fortunately it was seen later by quite a few people a little further down the coast. I think Carl, who knows far more than I do about these magnificent creatures, considers it most likely to have been a humpback whale.

"I don't think anyone managed to photograph it though. I was very lucky to have been standing in virtually the same spot, at the end of East Bank, five years almost to the day, when a pod of twenty or more pilot whales swam east towards Sheringham. November is the peak month for whale spotting in Norfolk."