A drug dealer has denied being the mastermind behind a large-scale heroin syndicate. Wong Yut-wah, 43, admits being a conspirator in making and selling heroin - but denies it involved 485 kilograms of the drug. James McGowan, defending, told the High Court that only five kilograms of heroin was involved, rather than the huge amount alleged by the prosecution. Mr Justice Patrick Chan ordered a special hearing to enable him to decide the true extent of the conspiracy. Wong's accomplices, Lo Chong-wing and Ko Lai-cheung, are to give evidence to the High Court today. Lo and Ko, arrested in July 1995, have been in custody pending sentence for trafficking ever since. Mr McGowan claimed the two men were hoping to win a reduction in their sentences by exaggerating the amount involved. Wong pleaded guilty to conspiring to manufacture and traffic in heroin. Prosecutor Peter Lavac said the plot lasted from July to November 1994. But Wong claims it was a much shorter-lived conspiracy, lasting less than two months.