Yesterday we met special canine agent 'Charlie', a Labrador whose sole aim in life is to find whatever his owner wants him to find....all in return for his favourite thing in life - a tennis ball!

Charlie is a police dog from Cambridge, UK. He is now retired but he has many big claims to fame as a police dog, including finding drugs worth £250,000.

We met more dogs just like Charlie who are trained to sniff out explosives, drugs and also to find missing people. We met their handlers too, who take the dogs home every night and keep them as members of their families when they are not tennis ball hunting.

We filmed a great article for you about how the dogs are trained. We found out that the police work with many different breeds of dog including Belgian Shepherds, German Shepherds, Spaniels and, of course, Labradors. We also heard about how they often take on dogs from rescue centres and train them up through the 13 week training programme to become canine 'special agents'.

We look forward to sharing the article with your in the coming months.