Mystery surrounds the appearance of a number of washed-up sharks on a north Norfolk beach.

Jonathan Sweatman, from Walcott, found five dead fish while walking on the beach near his home on April 30.

Mr Sweatman found another fish of the same type alive, which he put back on the water.

The creatures are commonly known as dog fish, which is among the best-known species of the Squalidae family of sharks.

Mr Sweatman said he did not know what could have caused the fish to wash up.

He said: “It didn’t make sense, especially the one that was alive. It wouldn’t be seals as someone suggested as they were not bitten.”

The fish were found around 9am, close to low tide.

Mr Sweatman said the fish were around 18 inches (45cm) long.

He said it was not the first time he had found such fish washed up the beach between Walcott and Happisburgh, when out taking his daily exercise.

He said: “This is the second time in the last 10 days I have found some on the beach, none had any signs of predation.”