Londoners stunned by what appeared to be a crocodile in the River Thames

The 'crocodile' seen floating in the River Thames. Photo / Twitter

A London dog walker was stunned when he spotted what appeared to be a crocodile in the River Thames.

The reptilian object was snapped floating near Chelsea Harbour by a boat's propeller.

But the harbour master was quick to shut down claims of a crocodile floating in the Thames, pointing out that it wasn't real.

Dog walker Chris Davies told The Sun: "Two guys were looking at it as I walked towards them with my dog.

"One of them works for Chelsea Harbour Estate and said the police had been called."

He said he was amused by the sighting, saying: "It's not a big one so I was amused more than anything else. He's floating around the 'Esperance'."

Harbour master Colin Bullock said: "A pond ornament has been disposed of, as simple as that.

"It's not real."

The foot-long ornament, which was just a head, had to be fished out with a net.

A RSPCA spokesperson said: "We haven't received any calls to our emergency hotline about a crocodile in the River Thames, however we have seen a video circulating on social media.

"It would be very unusual for a crocodile to be living in the River Thames and it's difficult to tell from the video if it's real or not.

"We would encourage anyone who spots the crocodile to contact the police in the first instance. We are happy to provide animal welfare advice, if necessary, if the animal does turn out to be real."