There is growing demand for heroin in China itself

They have also arrested 18 members of Tan's armed gang and seized three tonnes of heroin.

State-run media is calling this the biggest coup against the Golden Triangle drug gangs in nearly half a century.

For nearly 10 years, Tan had been running what the media are describing as the biggest armed drug smuggling group inside the Triangle.

From there, the gang shipped large quantities of heroin through South-west China to Hong Kong and then on to the rest of the world.

Preferred route

Tan was caught in April, after a year-long man-hunt which China says involved close co-operation with police in Burma.

China has long been the preferred route of Burma's drug gangs to get their product to the outside world.

But in recent years, China itself has started to become a major market for the heroin producers.

Drug addiction is now a serious problem in many of China's cities.

It has prompted the authorities in Beijing to take a much tougher line against the drug gangs and to strengthen co-operation - not just with Burma, but also with Laos, Thailand, Cambodia and Vietnam.