The dead-looking rodent was pictured on a pink spade and tweeted by BBC Radio 2 yesterday.
Debate has raged over whether the photo might be a totally different rodent altogether, one pest control expert saying it could be a rodent known a beaver-type animal known as a coypu.
Another animal specialist claims it is an "oversized, brown rat" mutated from the increase in food waste.
BBC Radio 2 posted a photo of the dead-looking rodent on a pink spade on Twitter, from a listener known as "Sarah" days after the Daily Mail reported rats "the size of small cats" are invading cities and are immune to poison.
Ben Johnson, who is director of Direct Pest Solution, based in Trosley Avenue, Gravesend, believes it is another animal altogether.
He told News Shopper: "I don't think it's a rat, I believe it's a coypu, a bit like a beaver.
"We certainly haven't had any reports of giant rats."
It is originally from South America, but has now been introduced to Europe, North America, Asia and Africa.
However, rare breeds expert Wayne May, based in Dartford, believes the photo shows a rat.
He said: "The picture looks like a large, oversized brown rat due to current climate and the increase food waste.
"It is not uncommon to this species weighing around 1.5lbs or more in the UK
"Large rats are increasing being recorded."
News Shopper readers waded into the debate.
Former Labour MP John Austin tweeted: "Could be coypu if it has webbed hind feet.
"I've had Pâté de ragondin (copyu) in France. Very good."
Puddy Tat, known as @Catford_Cat, tweeted, perhaps not entirely seriously, that the picture showed a Siberian hamster.
Source: News Shopper
I looked at the pictures of Coypu in Google and the creature on the showel does not look like one, since the shape of the head is different the texture of the fur is different. A brown rat of sorts appears like a better option. But we really don't know the size of it, because we don't know the size of the showel and so there is little to compare with. If they wish to prove it is big why not measure it?