A global crackdown on the movement of a key ingredient in the manufacture of cocaine has put a significant dent in the worldwide trade in the drug, a conference in the SAR heard yesterday. Shipments of almost 1.7 million kilograms of potassium permanganate - used as an oxidising agent in the production of cocaine - have been seized or stopped in a six-month operation involving the SAR and 16 other governments. Drug investigators from around the globe - who have been meeting in the territory for the past four days - estimate the haul could have stopped the production of 17 million kilograms of the drug worldwide. The United States and China are two of the world's major producers of the chemical and Hong Kong is a significant transshipment point. The success prompted the three international organisations and 17 governments represented at this week's conference to expand and extend the operation which was due to end this month. Those involved, including the US Drug Enforcement Administration (DEA), were major potassium permanganate producers in the US and China, and Customs representatives of transshipment ports such as Hong Kong, and Colombia, the world's leading cocaine exporter. The chemical also has legitimate uses such as water purification and the group has also discussed ways of co-operating to avoid hindering its legal export and import at an earlier group meeting in Madrid, Spain, in February. More than 4.8 million kilograms of the chemical transported in 173 shipments were tracked during the six-month 'Operation Purple'. Twenty-four shipments - carrying a total of 1.7 million kilograms of the chemical from seven producing countries - were seized or stopped during the operation. Terrance Woodworth, deputy director of the DEA's Office of Diversion Control said yesterday: 'It's going to disrupt cocaine production, affect the quality of cocaine and impede the traffickers.' The director of Colombia's National Directory of Drugs, Dr Gabriel Merchan, said they had seized 61 tonnes of illegally imported potassium permanganate and impounded six more. He said the operation would be a heavy blow to illegal manufacturers as every kilogram of the chemical could produce 10 kilograms of cocaine. The black market price for a kilogram of the chemical in Colombia jumped from US$75 in late 1997 to US$280 as a result.