POLICE are alarmed at a dramatic increase in loansharking in Eastern District. There were 14 known cases in the first quarter of this year, compared with 21 for all of 1992. This was a 180 per cent increase compared with the five reported cases during the first quarter of last year. Assistant district commander (crime), Detective Superintendent Don Logan, said: ''The so-called 'blood-suckers' are charging the borrowers exorbitant compound interest which goes from a minimum of 1,200 per cent per annum to a maximum of 18,000 per centper annum. ''This is extremely high compared with the legal limit of 60 per cent per annum.'' Officers in Eastern - which covers North Point, Shau Kei Wan and Chai Wan - said victims of the loansharks came from all walks of life but most were low-income earners. While many had resorted to illegal borrowing due to gambling debts, some just wanted quick cash. ''These are the people who can't obtain legal loans from financial institutions,'' Mr Logan said. ''We are not only concerned about threats, intimidation and even false imprisonment of the borrower, but also about the harassment of his or her relatives and friends.'' Of the 35 loanshark cases since 1992, 22 involved criminal damage, nine criminal intimidation, two unlawful detention and one false imprisonment. Of the 14 cases between January and March this year, 10 were connected with gangs from Macau. ''Hongkong people borrowing money from loansharks in Macau who mix with the casino-goers has been going on for a decade, but it has become more open, apparent and blatant in recent years,'' Mr Logan said. ''I can give you a Hongkong example, where a girl left her Chai Wan home at the age of 16 to work as a hostess in a karaoke lounge. ''She was enticed into buying some expensive clothes, and when she was unable to afford them, she borrowed $10,000 from the loanshark. ''Two days later she was asked to pay $15,000, and $30,000 two or three days later. Being unable to settle the debt, the girl was forced into prostitution,'' Mr Logan said. He said loansharking was one of the major sources of income for triads. ''Many triads are not only loansharks themselves but also operators of illegal casinos in Hongkong as well. ''Once people lose their money they are subjected to influence by the loansharks almost immediately.'' Police said the Wo Sing Wo and the 14K were active in Mongkok, the Fuk Yee Hing and the 14K in Eastern, and the Sun Yee On and the Luen Lok Tong (Lo Luen) in Wan Chai and Tsim Sha Tsui, controlling entertainment premises. If a debtor does not re-pay the loan, he is subjected to various degrees of threats from nuisance telephone calls, to assault and even unlawful detention of himself or his family.