Pc Tizer is said to be a valuable member of the team

Tizer was adopted by British Transport Police (BTP) from the Cats Protection charity in September and inducted into the force as an honorary constable.

In his role as the Chief Mouser Pc Tizer walks around King's Cross rail station to keep it rodent-free.

An "essential member" of the team, he has unfettered access to all areas and shares an office with a senior officer.

'Playing fetch'

Insp Roy Sloane, who enlisted the tabby, said: "Pc Tizer is already an essential member of the team.

"Since we got him we haven't seen any mice in the building at all... Prior to his arrival we were spending a fortune on pest control and it wasn't really working."

Insp Sloane said he visited the charity's adoption centre in north London with the aim of finding a cat to clean up the station's rodent problem.

He met Tizer, who arrived at the centre in August after his owner died.

Insp Sloane, who shares his office with Pc Tizer, added that his feline colleague helps other officers "de-stress" and has given a boost to the force's morale.

"Everyone is always asking after him, and he is probably the most popular member of staff," he said.

Cats Protection Adoption Centre acting deputy manager Alex Davies said: "He loves being around people, and likes nothing more than playing fetch with his toy spider."