A puppy dumped on the roadside in a cage at four months old has joined Surrey Police as a trained sniffer dog.

Chester the cocker spaniel was rescued by the RSPCA after he was found by a member of the public abandoned in a metal crate with five other puppies on a grass verge in Hersden, near Canterbury, in January.

The four cocker spaniels and two terrier crossbreed puppies were thought to have been abandoned after having passed the age when they are most marketable.

RSPCA inspector Clive Hopwood said: “It’s very possible these puppies were abandoned by a breeder. We believe these puppies may have failed to sell so they were abandoned having passed their ‘cute’ stage when they’re most marketable and most valuable.”

It quickly became apparent that Chester had “huge energy levels”, making it difficult for the RSPCA to rehome him, until volunteer fosterers noticed he had a real drive for “searching and sniffing things out”.

Sarah Piggott, who works for the RSPCA and fostered Chester, said: “No amount of walking or enrichment seemed to exhaust him.

“I realised he had a real drive for searching and sniffing things out when he’d easily find other dogs’ lost tennis balls on walks and kept bringing them to me.”

Tara Luxford, who adopted Chester’s brother, Bertie, said Chester was “always destined” to join the police to become a sniffer dog.

“I remember one day we were walking them together and Bertie had lost his new toy in a bush and we couldn’t reach it,” Ms Luxford said.

“We told Chester to ‘find it’ and he went straight into the bush and got it back for Bertie.

“He was always destined to be a sniffer dog.”

In March, Chester was taken in by Surrey Police and began the process of training to become a sniffer dog with a special foster family.

Ms Piggott said she was “so proud” of her former foster puppy and added she is “thrilled” he has finally been rehomed.

“Chester has done really well and caught up to the other puppies who were bred to be sniffer dogs and started their training before him,” Ms Piggott said.

“I’m so proud of him and I’m thrilled that he’s found a home where he can do what he loves every day while being well looked after.”

After completing a six-week intensive training course, PD Chester became a licensed police sniffer dog in October and he was celebrated at a ceremony at Surrey Police HQ.

The “amazing” pup has now been deployed across Surrey and Sussex to support the police alongside his handler PC Kim Hackett.

Surrey Police operational and dog school manager Geoff Wiltshire said: “Chester has been amazing since he arrived with us.

“He has gone from strength to strength and has done really well to pass his digital detection course.

“Our standards are very high and he has proven himself to have all the necessary qualities to succeed in this important role.

“His handler, Kim, has a great bond with him and we look forward to seeing some operational results from this new team.”