Burrowing deep into a huge pile of jumbled luggage, Dick the dog wags his tail, pawing at a small green rucksack: inside is the hand-sized tip of an elephant's tusk.

Sniffer dogs have long been used to seek out drugs and explosives in airports, but now Kenya has deployed specialised dogs trained to find elephant ivory and rhino horn in the latest bid to stem surging wildlife crime.

This time, the hidden ivory was part of a training exercise, a test that Dick -- a Belgian Shepherd, or Malinois breed -- passed with flying colours earning a rub from his handler.

Conservationists say the dog teams open a vital new front in the war on smuggling, increasing the risk for criminals.

Earlier this year, in just one week, the dog team sniffed out four separate bags -- travellers from China, Thailand and Vietnam -- carrying ivory home.

"It speaks volumes if you can arrest people like that consecutively," said Mark Kinyua, who heads the dog unit for the government's Kenya Wildlife Service (KWS). "It is a huge deterrent."

- 'Poaching crisis' -

The dogs' sensitive noses can smell out the tiniest pieces of carved ivory, which otherwise might have passed through the busy airport unnoticed.

"Arrests have been for worked ivory, in the form of bangles and pendants and even finger rings," Kinyua said, adding that recent cases include pendants wrapped in aluminium foil, in the hope of hiding its scent from the dogs and its shape from X-rays.

"Others were hidden in a cigarette pack, another in a suitcase," Kinyua said. "That is where the dogs come in, and they make the arrests for us."

More than 30,000 elephants are killed for their ivory every year in Africa to satisfy demand in Asia where raw tusks sell for around $1,100 (1,000 euros) a kilogramme (2.2 pounds).

Kenya plans next month to torch its vast stockpile of 120 tonnes of ivory, eight times the size of any ivory stockpile destroyed so far.

A single piece of ivory jewellery may therefore seem little compared to tonnes of raw tusks, but when dogs are making regular busts, shutting down smuggling routes used by tens of thousands of travellers each day, it makes a big difference.

"We are in a poaching crisis," said Philip Muruthi of the African Wildlife Foundation (AWF), the conservation group which trained the dogs now deployed at Kenya's ports and transit routes.

- Incorruptible -

In a trade dominated by organised crime with very deep pockets, dogs like Dick have skills unmatched by humans. While dogs have been used to sniff out wildlife smugglers before, these dogs were specifically trained to hunt down ivory and rhino horn.

"You cannot corrupt a dog, once a dog makes a find, you cannot tell him that it is not ivory," Muruthi said, noting that even if rhino horn was ground into powder, it would make no difference. "What the dog is detecting is the scent."

Each dog is far from cheap to train and keep, as much as $6,000 (5,500 euros) per animal, all-in.

But conservationists point to the far larger costs of poaching. The dogs have already paid for themselves several times over, as a single bust can result in fines of $10,000 (9,200 euros) as well as imprisonment.

"He is not just a dog, but part of a larger plan to protect wildlife," Muruthi said. "We cannot have sustainable development in Kenya if we do not value conservation."

Six dogs operate in the airport, working in shifts to ensure bags are checked 24 hours a day. As well as ivory and rhino horn, they have also found impala skins, pangolins, and a tortoise.

- 'Advanced technology'-

"The dog is able to discriminate between ivory and ordinary cow bone because it has a very high sense smell," said Muruthi. "If you want to think of a dog as 'technology' we are applying here an advanced technology to detect contraband movement of wildlife products."

The programme is also operating in Kenya's Mombasa port, as well as in neighbouring Tanzania, all key smuggling routes for the wider East Africa region.

There are plans to extend their use into Uganda, Mozambique and Ethiopia.

For the dogs, such as Asha, a spaniel, running along carousels in the opposite direction to the baggage, leaping over suitcases as if they were an obstacle course, the work looks like a game.

"Show me, show me where," the handler calls in encouragement, as the dog turns to check, while KWS teams read luggage destination labels, marking out bags heading for suspect cities where smuggling is common.

Flights coming from Democratic Republic of Congo and Mozambique, and those heading for the Chinese city of Guangzhou, are given special attention.

"Because this is a travel hub, we expect to not only catch ivory that is coming from elephants killed in Kenya," Muruthi said.

At current rates of elephant killing, many fear large herds of elephants will be wiped out within decades from all but the most protected of parks.

"It is totally unsustainable," Muruthi said. "Can you imagine Africa without elephants?"