Two sniffer dogs trained to detect the smell of rubber from a dinghy have helped intercept more than 120 small boats heading into the English Channel.

Two German shorthaired pointers, Anya and Adele, are stationed at the world’s second busiest land border crossing between Bulgaria and Turkey to detect rubber boats that trafficking gangs are trying to smuggle into Europe by truck.

The National Crime Agency (NCA) commissioned chemists to distill chemicals from the rubber of an inflatable boat, which dogs were trained on to detect them rather than the usual targets of explosives, drugs or weapons.

Their deployment at the Kapitan Andreevo border crossing in southern Bulgaria helped national authorities and the Bulgarian Border Service carry out 33 separate interceptions of maritime equipment intended for criminal gangs organizing the crossing of the English Channel.

The national competition authority said it had intercepted 125 inflatable boats, each of which would carry up to 80 migrants across the English Channel, equivalent to up to 10,000 people. Also seized were 128 outboard engines, more than 700 pumps and 300 rubber rings.

NCA analysts estimated that the seizures would deprive criminal networks of around £16.6 million of the profit they would have made at border crossings using the equipment.

Dame Angela Eagle, the border security minister, said intercepting the dinghies could save lives. “By seizing equipment used in dangerous and weak boats, we are also dealing a serious blow to smugglers’ activities and cutting off multi-million-dollar profits,” she said.

Both dogs are handled by the Bulgarian Border Guard after being trained by the competent national authority. Dogs can be trained to detect up to five scents. One of them is “Eau de small boats”, as the officers jokingly call it. The UK is also paying for high-tech scanners to detect equipment hidden in trucks.

Turkey is a key supplier of the boats, which are built in back-alley factories from materials and engines imported from China and then transported by truck and van to Germany, where they are stored ready for use by people-smuggling gangs operating in northern France.

Until recently, they were openly transported into Europe as supposedly legal boats, but border forces and law enforcement agencies across the continent have begun to take a tougher approach and have begun confiscating the inflatables, claiming they are so weak that they violate health and safety regulations.

This forced gangs to try to hide them in the holds of trucks. As a result, Bulgaria has not only introduced new laws allowing it to seize and confiscate unseaworthy boats, but is also using Anya and Adele and scanning technology.

The national competition authority’s director of intelligence, Adrian Matthews, said: “Bulgaria is a key supply route location for criminal people smuggling networks involved in organizing dangerous boat crossings across the English Channel.

“Removing this equipment before it reaches them not only disrupts their operations and hits their profits, but also prevents these deadly boats and underpowered engines from being used at sea where lives are at risk.

“As close partners and allies, the UK and Bulgaria work together to fight organized crime and illegal migration, strengthening both countries’ border security. Together, we are determined to continue to do everything we can to dismantle and dismantle people smuggling networks that profit from misery, wherever and how they operate.”

Georgi Gospodinov, head of customs at Kapitan Andreevo BCP, said: “Joint exercises with UK law enforcement partners are extremely important to us. Sharing good practices is a guarantee of good results in effectively combating smuggling and illegal channels of trafficking in human beings.”

Broaden your horizons with award-winning British journalism. Try The Telegraph free for 3 months with unlimited access to our award-winning website, exclusive app, money-saving offers and more.