Fierce crackdowns by police and a plant replacement scheme have reduced poppy planting and processing operations to some extent. Since the late 1990s, coffee, castor beans, cassava, rubber and tea have been used to replace poppy plantations. After 10 years, these substitutes are beginning to generate profits, giving local farmers a viable alternative to growing poppy.

One mu (667 square meters) of poppy yields about one kilogram of opium a year, which could be sold for 1,800 yuan (US$224), enough to feed a rural family of six. But these days, growing poppy is no more profitable than growing tea. One mu of tea could earn 4,000 yuan this year if weather conditions permit.

As a result of the plant replacement scheme, the raw materials for drugs such as heroin have become increasingly harder to come by and more expensive, thereby affecting their street value. A kilo of heroin, 90 percent purity, reportedly sells for 20,000-plus yuan in Laos, 60,000 yuan in Vietnam, 80,000 yuan at the China-Vietnam border, and up to 90,000-100,000 yuan in south China's Guangdong Province.

In addition to price, authorities have noticed a change in consumption habits. According to statistics from international anti-drug agencies, the sale of new types of narcotics such as synthetic drugs like Ecstasy has increased in tandem with a decrease in the supply of traditional drugs like heroin, cocaine and cannabis.

According to China's State Anti-drug Committee, mainland customs cracked 23 cases of synthetic narcotics trafficking in the first quarter of this year, accounting for half of all drugs smuggling cases. The seized narcotics, weighing a total of 48.7 kg, included methamphetamine (also known as ice or crystal meth), ketamine and Ecstasy.

However, drug traffickers have dealt authorities another challenge; they are bypassing the need for physical smuggling through the use of the Internet, International Herald Leader reported on May 23.

More and more synthetic narcotics are being produced in homes, which is a result of manufacturing and processing technology being transmitted electronically via the Internet from bases in the Golden Triangle.

This year, local police seized 130 kg of synthetic drugs in south China's Guangxi in the first three months alone. A man named Xiao Chunfeng was found to have produced nearly 100 kg of ice, in his backyard, so to speak, according to local police.

Liang Yiling, an expert who has been engaged in collecting drug sales information for many years, said that the chemicals needed to make synthetic drugs are readily available.

For example, green tea polyphenol, which can be processed to make caffeine, is not classified as a controlled substance because it's commonly used in soft drinks and medicines. Tea polyphenol is also one of the main ingredients of ice.

With 60,000 yuan worth of tea polyphenol, Xiao Chunfeng produced 10,000 pills of ice, with a wholesale price of up to 280,000 yuan.

Processing techniques aside, sales channels have also opened up on the Internet. Liang said that drug dealers even manage money-back guarantees, ingredients supply and money laundering services online.

Many of the deals are now done without any personal or physical contact, which has made it harder for authorities to trace and investigate cases.

"The traditional modes of drug dealing have changed greatly," Li Boping, a senior detective, said, adding that there should be a more stringent management of the Internet by international enforcement agencies and also tighter controls on chemicals that can be used to manufacture synthetic drugs.