"Go on Rocky, find it! Good boy!" The labrador wags his tail, happy to have found the hidden treasure as he graduates from Italy's "truffle dog university", doing his master proud. Giovanni Monchiero is the dean of the unusual academy in Roddi in northwestern Italy and, like his father, grandfather and great-grandfather, transforms "normal" dogs into expert seekers of the lucrative fungus.

"Teaching a dog to find truffles is very simple, you just need plenty of patience and to realise that for the dog, it's a game," said Monchiero, 55. "We start by getting the dog to play with the truffle. Personally, I use a fresh truffle, but if you don't have one you can put some truffle-scented oil on a tennis ball. You throw it, the dog has to retrieve it and you reward him with dog biscuits."