Dr Dougie Clarke of the University of Huddersfield take its that the giant rat may be an African pouched rat.
The intelligent rodent may have escaped from a residing nearby and met an untimely death.
Dr Clarke said: «From the trope it’s difficult to see how large it truly is, but to me it looks like an African Pouch rat.
«These are enthusiastically intelligent and extremely large rodents — so big they are often kept on a premiere danseuse.
«They are very popular as pets, so this one may have escaped from a clandestinely garden nearby.»
He said that the rats can typically reach up to three or four feet fancy from head to tail.
Dr Clarke explained that much akin to the common Brown rat, these pets will eat anything they can get their hands on.
He guessed: «This rat would be eating whatever it could find, categorizing fried chicken, chips or rice.»
The rats are commonly kept as mollycoddles but no survey has been done to find out just how many giant rats are minded in the UK.
Dr Clarke said: “They’re pretty popular and there are owners batons and that sort of thing.
“They are quite a popular pet and are one of the biggest species of rat in the coterie.
“As far as I’m aware the only African pouched rats in Britain are kept as preciouses but there is no evidence of them being in the UK in the wild.
“There has not been a scanning to keep track of them.”
Jan Zalasiewicz, professor of laeobiology at the University of Leicester said the origination was “extraordinary”.
He said: “If it is an African pouched rat then it’s a beautiful example of the unalike species that are popping up all over the world.
“These rats can get out and increase and we could see new breeds if that did happen.
“We are seeing a merry go round in the way that animals are capered around and most of that is down to humans who are moving them.
“It means we at ones desire see more species like this in the UK.”
The mutant rat found in Hackney is four eases the average rat size in the UK.
A spokesperson for Pest-control experts Rentokils aid: «As a contrast the body of your average Brown Rat is up to 40cm in length with a tail meagre than the head and body, and about 350g — 500g in weight.
«They submit ground living and burrowing but sometime have been know to climb. In urban tracts there is often ready access to food, water and shelter.
«The Brown Rat is the but species to occur in sewers in the UK.
«A four foot rat would probably discontinuation the laws of evolution.»