Business in West Africa is booming - for drug traffickers, at least.
The region has flourished as a drug trafficking hub in recent years as cartels exporting narcotics from Asia's "Golden Crescent" and South America to the rest of the world exploit its poor population and weak law enforcement.
For US$10,000, drug mules in West Africa will swallow up to 2kg of cocaine or heroin, wrapped in plastic, and cross the border into Hong Kong, according to a government source.
"Most of them are low-educated workers and have never travelled overseas," the source said. "The amount is so attractive to them. It is as much as they could earn in 10 to 20 years."
Half of the money is paid before they leave their home country. The rest comes when - or if - they successfully reach their final destination.
Hong Kong customs officers picked up dozens of people at Chek Lap Kok airport last year who had concealed drugs in their bodies.
A veteran customs officer said drug mules swallowed and passed drug pellets beforehand to determine the amount they could tolerate in their bodies.
"Each [mule] could swallow at least 1.5kg of illegal drugs in pellets. They were also given antidiarrhoea tablets in a bid to stop any accidental discharges during the long journey," he said.
Cartels source cocaine from South America and opium from the Golden Crescent - a space that overlaps Afghanistan, Iran and Pakistan - and smuggle the drugs into West Africa. The drugs are then delivered to Hong Kong via the Middle East.
Last year, customs officers at Hong Kong airport seized 66.6kg of heroin, worth HK$58 million, and 57kg of cocaine worth HK$75.7 million.
Customs have vowed to continue stringent controls at entry and exit points to prevent drug trafficking. It will maintain close intelligence links with mainland authorities and overseas law enforcement agencies to clamp down on drug crime, it said.