CHINA'S official news agency yesterday questioned some of the sentences meted out by Hong Kong courts concerning recent horrifying crime cases. Referring to the spate of crimes such as the ''barbecue case'' and the Tuen Mun serial rapist, Xinhua (the New China News Agency) said in a rare commentary the sense of security of local people had been damaged. ''There are, of course, a number of reasons behind the growing number of crime cases. But to many residents here, they believe that one major reason is that the sentences given to the convicted persons are improper or too lenient,'' it said. Xinhua cited a survey conducted by a newspaper which found that 88 per cent of respondents were not satisfied with the jail terms imposed by the court to a property agent and his female. A Tuen Mun businessman Hon Leung-fong was found guilty of killing Baptist College student Elaine Luk Yee-ling with chloroform after luring her to a hotel under the pretext of attending a birthday party in July last year. The pair were convicted of manslaughter this week. Hon was sentenced to 81/2 years in jail and his mistress, Phoebe Wong Yim-ping, who helped videotape Hon's sex attack on Luk, was given seven years. Xinhua said: ''Many people said the sentence was too lenient and there was no fairness and justice. If it [the problem of lenient sentences] is allowed to continue it will not be able to effectively curb serious crime. The dignity of law and the Judiciary will be damaged. ''Why has a rapist who ganged up with a group of people to rape a 17-year-old girl been sentenced to four years because of his 'good character'? Why was the defendant in the barbecue case only given a six-year jail term because he had no 'motive to kill' and had volunteered to admit guilt? ''Why have similar cases of murder in Vietnamese boat people camps resulted in one being sentenced to life imprisonment and another to a four-year term?'' In the barbecue case, a roasted meat seller was sentenced to six years in July after she was convicted of chopping her lover's wife after burning her in the bath. The sentence has triggered a mass signature campaign by the victim's family for a review of the sentence.