THE murdered daughter of the Director of Immigration, Mr Laurence Leung Ming-yin, had planned to launch a singing career in Hongkong later this year after finishing her studies in Vancouver, it was revealed yesterday. Miss Sylvia Leung Sze-hon, 22, was stabbed in a car park at the British Columbia Institute of Technology (BCIT). Her death happened six months into a police investigation into repeated vandalism at the family home. Vancouver arson detectives said they had previously warned the family they were being targeted, although no suspects were taken into custody in connection with those attacks. Detective Brian Hill said in an evening television news report: ''There was a very strong message that was being sent out. Whether it was intimidation, I don't know . . . ''This was not an amateur job. Whoever perpetrated it knew what they were doing.'' It was revealed yesterday that Miss Leung had signed a singing contract with Warner Music (Hongkong) late last year and was planning to return to the territory to begin recording in June. Miss Leung, who had been pursuing her education in Canada since 1989, was set to graduate from financial management studies this spring. The contract duration and amount paid for the deal are not known but people in entertainment circles said Miss Leung had a beautiful singing voice. Canadian authorities have yet to identify a suspect or motive in the murder, which happened on Sunday night (Monday morning, Hongkong time). Despite the series of attacks on the family in the past six months, the Royal Canadian Mounted Police maintain there is no direct link between them and the murder. ''At the present time, there is no connection between her death and those incidents, and I repeat, there is no indication that her Hongkong connections were a factor in her death either,'' Staff Sergeant Michael Eastham said, referring to Mr Leung's job in Hongkong. A grief-stricken Mr Leung said he had no idea who had murdered his daughter. ''I haven't got a clue,'' he said from his family house in Vancouver. Mr Leung also said there did not seem to be any connection between the murder and recent incidents of vandalism at the two-storey house. ''Presently, there are no indications that the two things are related,'' he said. Officers from the Vancouver City Police, who were involved in earlier investigations concerning the Leung family, said the homes of Mr Leung and his daughter's boyfriend, both on Vancouver's prestigious west side, were the targets of at least five incidents in 1992, including firebombings and an attempt to rig a front entrance with a dangerous electric charge. Arson detectives said the first attack on the Leungs, on August 28, came in the form of a fire deliberately set in two places, which destroyed the upper floor of their home on West 35th Avenue and caused damage estimated at almost C$100,000 (HK$605,000). The second attack, on November 5, caused C$15,000 (HK$90,750) damage after someone apparently used propane containers to set the rear of the house on fire. Also in November, Mr Leung's son, Hugo, moved to his sister's boyfriend's home nearby, awaiting repairs to the fire-damaged family house. But his car was firebombed near the boyfriend's house and, in a subsequent attack, someone broke into that house and wired the front door in an attemptto electrocute anyone who touched it. Later, the tyres of Mr Hugo Leung's car were slashed. Everyone then moved out of Miss Leung's boyfriend's house, which was put up for sale. Mr Laurence Leung, 51, and his wife and two children emigrated to Vancouver in 1989 although the immigration chief remains based in Hongkong. Mr Leung's department handles illegal immigrant and passport issues. He has been with the department since 1965 and was promoted to his present post in May 1989. Miss Leung had just left a campus building where she had been studying before she was attacked. Doctors said she bled to death after an artery was severed in the upper shoulder area.