POLICE have seized more high-grade heroin in the past three months than the total amount seized in 1993, causing wholesale drug prices to climb slightly for the first time in six months. The Narcotics Bureau says the local drug market is now choked with heroin that is about 35 per cent pure. Last month alone, police confiscated 128 kilograms of the drug. The total amount for 1993 was 223 kilograms. The increase was indicative of a continuing flood of heroin into the territory and more intensive police operations. Last month, police recovered 96 blocks of heroin worth $50 million from the seabed near Lamma Island. The 67-kilogram haul was the biggest for two years. Despite a month-long nautical surveillance operation, no arrests have been made. In early March, 33 kilograms of heroin was discovered in a hut at Yuen Long. There has also been an increase in the prevalence of the drug ''ice'', a synthetic crystalline methamphetamine. So far this year, 22 kilograms of ''ice'' has been seized, more than the total taken by police in the past two years. Last year, drug-related arrests rose by 44 per cent to 9,246. Deaths linked to the abuse of narcotics jumped by 34 per cent to 92. Narcotics Bureau Chief Staff Officer, Acting Chief Superintendent Iain Grant, said the extra drugs seized did not give police any reason for complacency. ''Obviously, if one measures success by seizures and arrests, then we can say both figures are up,'' Mr Grant said. ''But the other side is that there appear to be more drugs on the streets. ''There is always an element of luck in getting these results, but a lot of it boils down to good, old-fashioned police work.'' Mr Grant said police intelligence suggested Hong Kong was no longer as popular a transit centre for drug deals, but many transactions were still locally brokered or financed. He said he was particularly pleased with recent police efforts to destroy drug-cutting centres - where pure heroin is diluted for extra profits and ease of consumption by addicts. In 1993, 30 such facilities were located and shut down. This year seven have been identified. The Commissioner for Narcotics, Alasdair Sinclair, has indicated his alarm at the rapid rise in the number of registered drug addicts. Last year's figures from the Central Registry of Drug Abuse showed a distressing 15 per cent increase in the overall number of registered addicts.