A police force could become the first in the UK to introduce cats alongside its dogs in the fight against crime after a five-year-old wrote to the chief constable suggesting they should team up.

Eliza Adamson-Hopper received a reply from the Durham police chief, Mike Barton, thanking her for the suggestion and saying he would pass the idea on to an inspector. Barton included a drawing of his cat, Joey, on the back of his handwritten letter.

Insp Richie Allen, of the dog support unit, has confirmed the force will consider using cats in an as-yet-unspecified role.

Allen said: “I can confirm the force is looking into recruiting what we believe to be the first UK police cat. Their duties and responsibilities have not yet been agreed but if nothing else they will become the force mascot.

“Of course, if it smells a rat we’ll expect it to catch it.”

Five-year-old Eliza, from Burnopfield in County Durham, who has a cat called Mittens and a dog called Susie, wanted to know why the police do not use cats.

Eliza Adamson-Hopper playing with her cat Mittens. Photograph: Cheryl Adamson/PA

Her mother, Cheryl Adamson, said: “Eliza has loads of questions for everyone and I don’t always know the answers. We said she could write a letter.

“We typed out a letter to the chief constable, she told us what to write, and we said she might not get a response because he is a busy man … When we got a reply it was so sweet.

“It was not a bog standard response, it was really personal to her, and we loved the drawing of the cat, it really tickled us.

“Then the inspector from the dogs unit sent her a calendar and invited her to an open day.”

Since then her daughter has decided to raise funds for the retired police dogs charity Paws Up.

A police spokeswoman told the Guardian it was not an April Fools’ Day prank. Previously, British transport police adopted a cat, Chief Mouser PC Tizer, who was responsible for patrolling King’s Cross rail station to keep it rodent free.

Globally, this would not be the first time a cat has joined bobbies on the beat. Lemon, a former stray, was made an honorary police officer in Kyoto, Japan, after wandering into Yoro police station. He was even given his own uniform.