Five police dogs and their handlers will soon be joining a three-county fight against drug dealers after successfully completing their training.

Not all the dogs, labradors and spaniels aged between 12 months and two years, which began the six-week course to qualify for the unit patrolling in Herts, Beds and Cambs made the grade – six started the course which finished on Thursday.

Two were ruled out during training, while one extra recruit was added to the class.

But now Billy, Charlie – the late arrival who was renamed by the public – Duke, Pearl and Tank have all officially joined the unit as licensed police dogs.

As well as learning how to detect drugs, they have also been trained in seeking out cash and ammunition.

Assistant chief constable Mike Colbourne presented the handlers and their partners on four paws with certificates recognising the completion of their training, saying: “The dog unit’s training staff should be extremely proud of their efforts in producing five brilliant new assets.

“I hope the handlers who took part in the course are proud of what they have achieved and I hope they and their dogs enjoy a varied and enjoyable career with the team.”

One of the instructors, PC Jason Keir, said: “Although two of the dogs were not suitable for the training, it is absolutely fantastic that the course has seen five dogs and their handlers pass.

“These new drug detection dog teams will work across the three forces and provide invaluable support to officers. Tasks that might take an officer a number of hours to complete, such as a searching a house, can be quickly and thoroughly completed with a dog due to the high level of training they have received.

“For the dogs it won’t really seem like work at all, more of an extension of a favourite game, but for us their amazing abilities are essential to our work, so we ensure the dogs are kept stimulated and place their welfare as our highest priority.”