Thailand is facing an epidemic of drug smuggling in a complex international racket that appears too massive and entrenched for authorities to stop.

Police said on May 2 that they had seized 1 million illicit methamphetamine pills, weeks after discovering nearly 50 million legal tablets to treat common ailments had been stolen from Thailand's hospitals, to make powerful speed drugs to sell to addicts. An additional 2 billion similar tablets to treat common colds have been smuggled in from Taiwan and South Korea, also to make illegal drugs, authorities said.

Corrupt chemists and drug dealers have been extracting ephedrine and pseudoephedrine from legal cold remedies and similar medicines in Thailand and secretly shipping it across the border into Laos and Myanmar, also known as Burma, where gangs use the ingredients to create a range of amphetamine-based drugs.

Myanmar's drug gangs work among heavily armed minority ethnic insurgents including the Shan, Wa, and other tribes in the lawless, mountainous jungles near the border where the two countries meet.

Ephedrine and pseudoephedrine are used to widen bronchial passages and relieve asthma, hay fever, nasal congestion, allergies and the common cold but can also be a precursor chemical to manufacture methamphetamines.

Officials estimate one legal cold tablet's ephedrine or pseudoephedrine can be cooked to make three or four methamphetamine pills, enabling gangs to rapidly multiply their output. The speed-like pills they make are then illegally smuggled back into Thailand and sold to users, or distributed to other countries.

Investigators say they achieved a major breakthrough in February when they found big piles of empty wrappers for cold remedies -- but no pills. Many of the empty packets were shredded and dumped in a northern forest near Chiang Mai city. The packets could have contained up to five million tablets from 10 different remedies, police said.

Investigators traced the labels to several hospitals, where staff were suspected of siphoning off huge amounts of medicine from legal stocks in their pharmacies to sell to smugglers. The Department of Special Investigation (DSI) -- Thailand's version of the U.S. Federal Bureau of Investigation -- joined police to question hospital staff, government officials, and others and were reportedly inspecting more than 875 hospitals.

The numbers of pills -- legal and illegal -- are staggering.

"Up to 48.3 million cold pills are thought to have been stolen from [Thailand's] state hospitals and smuggled across the border to make methamphetamines," the Bangkok Post reported on March 29.

A medicine purchasing staffer at one northern hospital allegedly confessed to forging his director's signature to order more than 210,000 tablets, the DSI said in April.

In the latest case, Bangkok police searched a townhouse on Wednesday (May 2), discovered one million methamphetamine pills, and arrested two people, according to the Narcotics Suppression Bureau's Commander, Police Lt-Gen Chaiwat Chotima.

The building was a secret storeroom for pills brought to the capital from northern Thailand, Lt-Gen Chaiwat said, but it was not immediately clear if the drugs were made from pilfered ephedrine and pseudoephedrine.

Police meanwhile said they seized more than 200,000 speed pills in a truck at a supermarket's parking lot near Bangkok on April 13, just before the drugs were to be delivered to a dealer.

Bigger discoveries in April came when the DSI said two Thai companies allegedly forged documents to smuggle at least 2 billion pseudoephedrine-based cold tablets to Bangkok from Taiwan in 2009, amid plans to bring in an additional 8 billion pills. The DSI said the two companies also bought 85 million cold tablets from South Korea, smuggling the medicine on nine separate flights to Bangkok, starting in 2010.

False air cargo manifests allegedly deceived customs agents by describing the shipments as equipment for Thai companies which supplied electronics and automobile parts. One of the companies, which legally imports electronics, said it was innocent and blamed criminals for stealing its logo and company name to buy the tablets.

"After we appeared in headlines about pseudoephedrine smuggling, we have faced damage from intensive inspections of our products by customs officials," said UTAC Thai Co. Ltd.'s deputy managing director, Thanakhom Chawasiri.

"We have to keep on probing the case because the company's name appears in drug purchases from South Korea and Taiwan," DSI Chief Tarit Pengdith told reporters on Friday (April 27), apparently correcting earlier reports which pointed to China as a major source.

Tarit said he obtained evidence from drug officials in the two east Asian countries, and acknowledged that the company's name may have been misused by criminals.

To strangle the supply of ephedrine and pseudoephedrine, Thailand in April announced a ban on the public sale of medicine containing the inexpensive chemicals -- but the ban created a problem for hospitals and pharmacies trying to treat patients.

The Public Health Ministry ordered all drug stores and clinics to surrender medicines containing ephedrine and pseudoephedrine to health authorities by Thursday (May 3), and said about 6 million such tablets had already been turned in during April.

Future purchases of such remedies, including liquids such as expectorants, will need clearance from the Narcotics Control Division, it said.

Traffickers from Iran and elsewhere are meanwhile muscling in on the gangs by importing speed pills into Thailand and offering them for much cheaper prices, police said.

"There are very real fears the cheap drugs from Iranian gangs will be sold to customers in the lower end of the market," Narong Rattananukul, deputy secretary-general of the Office of the Narcotics Control Board, said on April 15.

Several Iranian men and women have been busted during the past several months while arriving at Bangkok's international airport, allegedly bringing in large supplies of methamphetamines and similar drugs.

Methamphetamines are more popular than any other illegal drug in Thailand, which is burdened with an estimated 1.2 million addicts who also include consumers of opium, heroin, marijuana and other drugs, according to the Office of the Narcotics Control Board. Thailand's meth users include thrill-seekers at nightclubs, concerts and parties, alongside students cramming to pass exams.

The pills are also swallowed by exploited workers at construction sites, fisheries and other industrial zones.

Slum-dwellers, transport drivers, diet-obsessed people and others are also buying the roughly produced pills which sell for about $6 each and are swallowed or smoked.

Methamphetamines abuse is so widespread that elephants are sometimes force-fed the stimulants to make them work longer hours while hauling logs, entertaining tourists, or performing other tasks.

Thailand's government, media and public popularly describe methamphetamines as "yaa baa" or "crazy medicine" because users sometimes exhibit bizarre or psychotic behavior.

Occasionally, a frenzied addict will seize a victim in public, and hold a knife to the person's throat, while screaming demands before being subdued, arrested and imprisoned.

(Richard S. Ehrlich is a Bangkok-based journalist. His websites are http://www.asia-correspondent.110mb.com and http://www.flickr.com/photos/animists/sets)