DESPERATE patients will not stop going to China to buy organs of executed prisoners until there are enough organ donations in Hong Hong, says legislator Dr Leong Che-hung. But he said it was also up to the Chinese authorities to control what he described as a disturbing practice. Dr Leong's remarks came in reaction to a Human Rights Watch/Asia report which claimed that executed prisoners had become the main supply source for China's organ transplant programme. ''It is difficult to know how many people from Hong Kong go to China for organ transplants, because many are not referred by a doctor,'' he said. ''But if they need an organ transplant to save their lives and cannot find a donor in Hong Kong, who are we to tell them that they should not go to China to get one?'' A study conducted by a surgeon at Prince of Wales Hospital found that 75 per cent of 26 kidney transplant patients from Hong Kong who underwent operations in China received organs from executed prisoners. But according to the Human Rights Watch/Asia report, prisoners' consent to organ donation was rarely sought before execution. Dr Leong said: ''The authorities in China must be made aware that this is morally wrong and be urged to take action to stamp it out. ''Although if Hong Kong had an adequate supply of donated organs nobody would have to take the risk of going to China to get a transplant.'' Despite campaigns to increase organ donations, donors are still in woefully short supply in Hong Kong. This has forced patients to visit the mainland for a transplant, although many Hong Kong residents who have undergone kidney transplants in China are known to have experienced serious medical problems after their operations. Dr Leong added: ''I am not saying organs from executed prisoners should not be used in transplants but we must be sure the prisoner's consent has been given without duress and there is really no way of ensuring this.'' The Hospital Authority has said it will accept organ donations from executed prisoners as long as there is proof of the prisoner's consent and no trading involved. The authority has already accepted kidneys and corneas from Hong Kong residents executed in a Singaporean prison, although it has not been offered organs by any mainland prisons. The issue will be on the agenda when a Hong Kong Medical Association delegation, including Dr Leong, goes to Beijing in October to hold talks with the Health Minister, Chen Minzhang, and the Chinese Medical Association. Dr Leong said it was also important that long-awaited legislation to ban trading in human organs in the territory was passed. The Human Organ Transplant Bill, which was first tabled in the Legislative Council in April 1992, is now expected to go through in October.