A GAMBLER went on trial yesterday accused of staging elaborate stings to cheat two businessmen at fantan. Kwan Yam-tong used an elderly friend to lure the men into playing, prosecutor John Dunn alleged in the District Court yesterday. He told them his gambling-addicted nephew was the intended victim of the sting to teach him a lesson, Mr Dunn said. But in each case the businessman ended up the loser at a cost of hundreds of thousands of dollars. Kwan denied two charges of cheating at gambling and two of obtaining property by deception. Mr Dunn said one victim, Li Tung-sung, met Kwan on business at an office in Central in November 1990. Kwan, who gave his name as Wong Ming-choi, introduced Mr Li to two other men called Chan and Lam, he said. Chan told him about his nephew, Peter. He offered Mr Li and the others US$20,000 and a gold medal if they could cure Peter of his habit, Mr Dunn said. Lam then demonstrated a ''foolproof'' method of cheating and persuaded Mr Li to put up $80,000. Mr Dunn said all five played the next day, but ''contrary to the plan, Mr Li lost the entire sum to Peter''. After Peter left with his winnings, Kwan told him it was a mistake and persuaded him to try to win back his losses. He handed over $40,000 and a piece of jade worth $300,000 in advance of the second session. But after he heard nothing more from Kwan he visited the Stanley Street office, only to find it empty, Mr Dunn said. There he came across Hui King-pui who told him he had fallen victim to an almost identical sting. Mr Hui lost $180,000 in the first game and then raised $150,000 for a proposed second game which never took place, Mr Dunn said. The trial continues.