A dog walker was met with a surprise yesterday morning when she encountered a mystery sea creature on Whitstable's West Beach.

Sally Browning, of Belton Close, came across the deceased animal while taking her dogs for a stroll at about 9am.

She posted a photo on Facebook, prompting much speculation as to what the animal was – with suggestions ranging from a newborn dolphin to a tuskless narwhal.

"It looked like it had been dumped there," said Mrs Browning, 40. "It was laying on plastic by the bin, and wasn't near the water at all.

"It looked decomposing. I had no idea what it was."

But Julia Cable, of the British Divers Marine Life Rescue charity, said the animal is likely to be a harbour porpoise.

"They are quite common around the coast, and sadly they do turn up on Kent beaches every now and then," she said. "It looks like it’s been dead a while."

The porpoise was reportedly removed on Wednesday.

On Tuesday, another dead porpoise was found inside a suitcase in Romney Marsh.

The UK Cetacean Strandings Investigation Programme advises that anyone who finds a stranded marine animal should contact either the RSPCA on 0300 1234999, or BDMLR on 01825 765546.