Last week we introduced new recruits Blade and Ice as the two German Shepherds starting their ten-week entry course to join Derbyshire police.

Unfortunately, Blade wasn't up to scratch.

Trainer PC Dave Heaps explained: "Blade just wasn't suitable for the job but we have managed to replace him with a part-trained dog from Preston called Nando. He's a two-and-a-half year old dog with a very nice temperament who so far is doing very well."

As Blade returns to being a family pet at his Sheffield home, Nando joined Ice for a trainee search mission in a disused ward at Derby's Kingsway Hospital.

We joined handlers Dean Allen and Paul Seymour along with trainer Dave Heaps as they checked the abandoned wards for dangerous objects that could harm the animals. Touring the building also helps distribute human scent, making it harder for the dogs when they begin their searches.

Dave Heaps explained: "We complete the exercise as if it is for real and we are lucky to have the use of this building as it contains multi-rooms and multi surfaces. With it being an old ward it also has lots of human scent. The dogs are learning to use their noses rather than their eyes.

"At the start I may hide within a room and as we progress I will be hiding under beds and even in cupboards and wardrobes. The dogs are learning to tag onto high concentrations of human scent."

For the exercise, Dave Heaps along with newspaper photographer Lindsay Colbourne, hid within different parts of the ward, as I joined Paul, Dean and the dogs outside.

The entire exercise was treated as a real incident, on this occasion we were hunting a wanted criminal, but the same method of search would be used if the dogs were searching for an injured or trapped child.

First into the ward was Ice and handler Dean Allen. Standing at the entrance to the ward, Dean ran through the warning commands: "Police officer at the door, come out before I release the dog. This is your last chance."

After waiting to see if the wanted person would be clever enough to hand themselves over, Ice was released from his chain.

As vicious barks rang through the expanse of the building, it was clear Ice had cornered today's volunteer culprit.

After a change of hiding place, it was time for Nando to prove himself. Handler Paul Seymour ran through the same warnings at the door before unleashing the dog.

Within seconds, barks again echoed through the building marking another success.

Trainer Dave Heaps added: "When the dog finds its object, it is trained to give out a good firm bark. The bark command is the same be it a criminal or a missing child, the dog is trained to indicate it has found someone."

To really test the animals, Dave upped the ante and hid under a bed for the next test. This ensures the dogs are using their noses rather than their eyes.

Yet again both dogs excelled, and new recruit Nando is fond of barking close to his found person.