A MERCHANT who sexually assaulted his 12-year-old daughter was lambasted by a judge for his 'ultimate betrayal' of 'the sacred duty of the parent to protect his offspring'. The father, 52, who denied indecent assault, was convicted and jailed for 15 months. He was found not guilty of two similar charges after his daughter claimed his other attacks were too 'disgusting' to put into words and refused to describe them in court. The District Court heard that in September 1993, the girl came home from school to find her family's Tsuen Wan flat empty. Her father arrived and went to his daughter's room. He came up behind her and fondled her breasts 'to see whether you have been molested by any boys'. She pushed him away. The girl claimed the incident was the first of many, but would not elaborate. However, the court was told he made a habit of touching her this way when her older sister went to China on business. The attacks became more serious in May 1994, when she was 13, and he assaulted her regularly until October 20, when her mother came home early and saw her husband leaving her daughter's bed. The woman became suspicious when she saw that her daughter appeared nervous, prosecutor Grace Chan said. The father was arrested on October 25 last year. Before passing sentence, Deputy Judge Tallentire worried about psychological damage the merchant had caused. 'Who can the child trust if she can't trust her own father?' In mitigation, lawyer Alan So produced a document bearing the signatures of 17 of his relatives and friends expressing their surprise that he had committed such an offence and pleading with the judge for leniency. Mr So noted the father was in the process of divorcing his wife. The conviction had cost him any chance of winning custody of his daughter.