THREE forgers risked the health of potential customers when they manufactured counterfeit heart pills, the District Court heard. Ng Cheuk-lam, 36, Lai Tsz-chuen, 35, and Lee Mo-hop, 55, pleaded guilty yesterday to possession for the purpose of manufacturing goods to which a forged trade mark was applied. They also pleaded guilty to possession for the purpose of trade goods to which a forged trade mark was applied. The fake heart pills were masquerading as Kyushin heart tonic - a Japanese product whose ingredients include hog bile, toad venom and pearl. The composition of the fakes remains a mystery, but Judge Candy said, regardless of chemical composition, ''such medicinal production, when carried out by an unqualified person, must carry the inherent risk that some physical damage might be done to consumers of the product''. The trio was arrested on November 25, 1991, by Customs officers, who also seized more than 1,500 bottles of counterfeit Tiger Balm, and more than 30,000 bottles of oils. The market value of the products was estimated at more than $1.3 million prosecutor Lee Cross said. The wholesale value of authentic Kyushin heart tonic was about $200 per box, and travelling salesmen were to have bought the counterfeits for $15 a box. Ng had hired three men to bottle and package the counterfeit oils, and had paid Lee $4,000 a month to deliver and collect the packing materials and finished products. Judge Candy took into account Ng and Lai's clear records and guilty pleas. They were given four-month sentences, suspended for two years. Ng was fined $150,000, while Lai received a $87,500 fine. Lee was fined $30,000.