TAIPEI security officials hope to discuss stronger co-operation with their mainland Chinese counterparts to stop the growing traffic of illicit drugs from China to Taiwan. Wu Tung-ming, director-general of the Investigation Bureau of the Ministry of Justice, yesterday told a symposium on drug crimes in Taipei that co-operation was essential. Mr Wu said the bureau had given information on seized heroin and amphetamines smuggled from mainland China to the Mainland Affairs Council (MAC), which would in turn pass the material on to the semi-official Strait Exchange Foundation (SEF). He said the data would be passed on to Beijing's counterpart organisations. ''In the future, we will discuss this issue together,'' he said. ''Drugs can't be sent to Taiwan. We need a positive development in relations with the mainland,'' Mr Wu said. He said that a large portion of the heroin smuggled into Taiwan came from mainland China, as did all the raw materials for amphetamines consumed in Taiwan. ''Whether these drugs are from the mainland is quite clear,'' Mr Wu said. ''The fishing boats come from the mainland and the packaging is clear.'' Mr Wu said drugs had definitive places of origin. ''Our labs can perform an analysis and tell where these drugs are from - just like fried noodles.'' Mr Wu said drug production occurred on the mainland because of the large land area and prospect of economic gains. ''Private use of illegal drugs is rife, and mainland authorities have not adopted aggressive measures to curb the traffic,'' he added. In a report to the symposium, Lin Ling-lan, senior special agent of the bureau's Economic Crime Prevention Centre, said Taipei authorities had confiscated 437.3 kilograms of heroin and 4.98 kg of marijuana in 1992. During the first six months of 1993, Taiwan police seized 791.4 kg of heroin and 20.68 kg of marijuana, Mr Lin said. He listed eight major cases of drug smuggling cracked by Taiwan investigative or police agents since August last year. In three of those cases, Taiwan fishermen had attempted to smuggle heroin apparently from mainland China to the island. The amount of heroin captured totalled 400 kg, including 329 kg in the first half of this year. Mr Wu also said that ephedrine HC1, an essential raw material in the synthesis reaction used to produce amphetamines, was entirely smuggled from mainland China into Taiwan. Other materials used by local illicit laboratories to produce the drug are obtainable locally. The symposium, attended by leaders of police and security organisations from 24 countries, is hosted by the investigation bureau.