Thai police yesterday launched a full-scale search for a Hong Kong man believed to be the leader of a heroin-smuggling ring. The hunt follows the arrest on Wednesday of a man with Hong Kong travel documents, Chang Seo-hwen, 40, who was held after 23.5 kilograms of heroin, worth 300 million to 500 million baht (HK$96.8 million to HK$161 million) was seized at a house in the beach resort of Pattaya, 150 kilometres south of Bangkok. Police said the gang had bought huge amounts of heroin for export to Australia, Canada, Hong Kong, Malaysia and Singapore. Chang was charged with intent to sell the heroin, but police said he had denied any knowledge of the drug. They said the alleged gang leader, who escaped the early-morning raid on the house, was using the name Liun Yun-dong. A third alleged gang member, believed to be Taiwanese, also escaped. Police added they had followed the gang for three months, and had blocked all main escape routes from Thailand. The gang barely escaped arrest on July 24 while trying to export 16.4 kilograms of heroin to Australia, they said. The latest find was concealed in 40 tightly packed tubes, which were in turn packed behind antiques gang members had marked for export. Police said Chang told them he had been hired to make the crates from planks under which some heroin was hidden - which apparently led to his downfall. Officers went to the Pattaya house after receiving complaints of sawing being carried out in the night. Chang is being held in prison in Pattaya for further questioning. He faces the death penalty if convicted.