VANCOUVER police revealed yesterday that a killer stalked and murdered Miss Sylvia Leung Sze-hon, the daughter of Hongkong's Immigration chief, with a powerful crossbow. The bolt penetrated her upper shoulder as she was about to open her car door. It is estimated the arrow was fired less than 30 metres away from the 22-year-old financial management student, hitting a main artery and causing her to bleed to death in the car park of the British Columbia Institute of Technology in Burnaby. Royal Canadian Mounted Police (RCMP) said the arrow, which cut through her body, was recovered at the scene of the killing, and they were hopeful that the public could help in locating the weapon and the killer. ''It is a unique murder weapon. A weapon like that is bulky, it's heavy and generally made of plastic. ''It is very difficult to destroy, and it is very difficult to hide,'' RCMP Staff Sergeant Michael Eastham said, displaying a similar weapon to the one which killed Miss Leung. ''To be accurate, one would have to have a lot of practice using this kind of weapon. ''We're estimating that less than 100 crossbows have been sold in British Columbia in a year, and hope that someone can come forward with information about a recent purchase or seeing someone practising,'' he said. ''One thing is for sure is that someone was after her. We believe the assailant was waiting for Miss Leung in the parking lot.'' Police said the tension on the type of crossbow that killed Miss Leung could be as high as 65 kilograms, and as an arrow left such a bow, it did so at nearly 300 kilometres per hour. The only other murder case in Canada involving a crossbow is now before an Ontario Provincial Court, where it is alleged that a man killed his wife in Ottawa using a similar weapon. Police also said an investigation into the licence requirements to buy such weapons should be pursued by the Canadian Government. At present, no licence is required to buy high-powered crossbows in the country. Miss Leung, whose father, Mr Laurence Leung Ming-yin, is Immigration director, had planned to launch a singing career in Hongkong upon graduation later this year. The Leungs emigrated to Canada in 1989 but Mr Leung remains based in the territory. Mr Leung, 51, was in Vancouver at the time of the killing to celebrate Lunar New Year with his family. Police said earlier that in the past six months the Leung family home in an upscale Vancouver neighbourhood had been the target of five vandal attacks, ranging from attempted arson to vehicle fires.