Police will seek help from their mainland colleagues to determine the identity of a decomposed human torso found washed up on a rocky beach at Cho Wan on Lantau. Pathologists identified the limbless remains as those of a man aged between 20 and 50, and said he had been dead for a week. The cause of death has not been ascertained. Senior Superintendent Gabriel Chan Wai-kong, of New Territories North regional crime unit, said that there were no distinguishing marks on the torso. Officers investigating the case are assuming the victim was murdered. 'We will check the records of missing persons in Hong Kong and conduct a DNA test to try to identify the torso,' Mr Chan said. 'The torso had been in the water for about five days. It is possible that the torso drifted for a long distance before washing ashore, and came from somewhere outside Hong Kong. 'We will seek help from authorities in Guangdong, and pass information to them through our liaison bureau, to see whether any human parts discovered on the mainland match the torso.' The torso was discovered by a construction worker on Monday afternoon. Police mounted a sea and land search for other missing body parts, but found nothing. The search was eventually suspended early yesterday.