Pest control officers in Bradford say there is no evidence of large rats in the city, after claims a 30in (76cm) rodent was found on a council estate.
The animal was shot dead on the Ravenscliffe estate, according to reports in The Sun.
It led to fears that large rats, or even a rodent species native to South America could be inhabiting the area.
Council officers visited Ravenscliffe on Thursday. A spokesman said: "We found no evidence of large rats."
Councillor Carol Beardmore said she was not aware of a rat problem, but had asked council officers to investigate.
Ms Beardmore said: "I live on the estate and while I'm not saying we don't have rats - everywhere has rats - I am not aware of an infestation of giant rats.
"We are not the Pied Piper of Hamelin round here with hundreds of rats.
Ms Beardmore, who represents the city's Eccleshill ward, added: "I am kept informed by officers on the council and only recently we did a survey and Eccleshill was quite low down the list regarding the number of rats."
She suggested the animal caught could be a coypu, a plant-eating semi-aquatic rodent originally native to South America.
Bradford Council's pest control manager Dennis Shipway said: "We have not received any reports of larger than normal rats or any increased rat activity in Ravenscliffe."
The estate is located close to a wood and has streams nearby.