UK Police heli ops are non public transport and so do not need fire cover, just like a pure freight flight do not need fire cover. Unless the 'company' flight manual says fire cover needed then non public transport can land take off with zero AFS CAT!
The Police Helicopter covering West Yorkshire operates from a purpose built base next to the M1 at Wakefield where there is no fire cover - and never has been!!
No different to your business man, who has his own helicopter parked next to his house.