West Africa has emerged as one of the key drug trafficking staging posts for the lucrative illegal market in Britain.

Drug runners are known to target vulnerable people, including women and children, to carry their wares across international borders.

These people, known as “mules”, will carry the drugs in their luggage, taped to their body or concealed in clothing. Drugs can even be dissolved in drinks.

The most notorious method of personal trafficking involve swallowing packages of high value drugs such as cocaine or heroin. A drug mule can swallow between 80 and 125 of these pellets with a total weight of up to 1.25kg, according to US customs officials.

They might be paid around £1,500, a tiny amount compared to the potential profit of hundreds of thousands of pounds to be made by gangmasters behind the scenes.

The payment is even less attractive when considering the terrible consequences if one of the packages, often made by filling condoms, should burst. The purity of the drug is often so high that the mule is killed by a fatal overdose.

UK customs officials have been so successful in targeting mules that the proportion of foreign women prisoners in British jails has soared.

A four-year project in Jamaica, known as Operation Airbridge, aimed to detect drug traffickers before they boarded UK-bound flights. It reduced the number of drug swallowers caught in the UK after flying in from the Caribbean country from about 1,000 in the first year to just five in the last 12 months.

Recently however the spotlight in the battle to block drugs from entering Britain has swung away from Jamaica. Last November the Ghanaian authorities teamed up with the British Government to improve training and bring in new equipment.

The country was the first in Africa to introduce high-tech scanning machines that can detect the faintest traces of cocaine and other substances.

Similar machines, which cost about £250,000 a year to run, are used at Heathrow and Manchester Airports. They can check up to 400 people an hour. They are so sensitive that they can identify a person who has handled money contaminated with cocaine.

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