He's one of 34 specialist sniffer dogs at Frankfurt Airport.

Max has been training for this work since he was a puppy.

His handler is trained to recognise his movements and his interest.

He can detect seven different illegal drugs by smell alone, and expects a reward each time he makes a find.

The trained professional begins his shift.

He's watched by his boss, Dieter Keller, head of the custom services dog training unit.

Dieter usually works with purebred Labradors, Alsatians and Malinois, but he made an exception when Max's intelligence caught his eye at a rescue centre.

A breech, Max is no breech.

It needs a lot of concentration to do this work.

To do this work is hard work for the dog.

Max runs the line, checking over 40 cases in just 100 seconds.

This flight is clean.

But Dieter has evidence of his canine crew's ability to sniff out narcotics.

A lot of money, hidden in a tiny package.

But the most sensitive detecting device in the entire airport allows Max to find it amongst the cases.

Human noses have 6 million smell receptors.

Dogs have 300 million.

But that's just the start.

A dog's nose contains a fold of tissue a human's doesn't have.

When dogs inhale, it forces air over their smell receptors.

The way they exhale is also different.

Humans force air out the same way it came in.

But dogs breathe out through slits at the side of their noses.

So they never have to stop sniffing.

In fact, dogs devote 40 times more brain space to analysing smells than humans.

As a result, a dog's sense of smell is 100,000 times more sensitive than their handler's.