A KITCHEN worker who tied up and raped a masseuse and then blackmailed her for $30,000 after taking degrading photographs of her was jailed for four years yesterday. Former sauna worker Ng Chi-hung originally denied raping the 33-year-old mother, but his trial in June was aborted when a juror fell asleep as the woman gave evidence about her ordeal. Yesterday, Ng, 36, changed his plea and admitted rape and blackmail, but denied three further counts of rape and two of stealing her wedding ring and $4,000. The High Court heard Ng attacked the woman on May 15 last year beating her up at her Kowloon flat and leaving her with at least 30 bruises all over her body. Ng had offered to sort out a row with the woman's former sauna parlour bosses who were demanding she pay compensation for breach of contract. Prosecutor Yasmin Mahomed said Ng kicked and punched the woman when she told him she had found someone else to settle the dispute. He then dragged her to her bed, ordered her to strip, bound her hands and feet and raped her. After untying her, he demanded the telephone numbers of her relatives, her apartment keys and $30,000. Later, Ng took nude photographs of his victim, which he threatened to send to members of her family if she reported the rape to police. Ng later sent a letter to her sister and her child minder. Enclosed in each was a photograph of the victim clothed, and a note demanding she compensate her former bosses, the court heard. Police arrested Ng after tracing him through a number left on his victim's pager. In mitigation, defence counsel Wong Chi-kwong said: ''The offences were committed on impulse when Ng lost his temper because he thought he had been made a fool of by the victim.'' He said Ng, a kitchen worker at the Caritas Medical Centre, had demanded $30,000 to pay back contacts he had already engaged to sort out the dispute. ''Fearing she would try to make a further fool of him, he was stupid enough to take nude photographs of her, but he never had any intention of using them to blackmail her,'' Mr Wong said. ''He only intended to use them to warn her not to make a fool of him again.'' Passing sentence, Deputy Judge Wilson said the offences appeared to be ''totally impulsive'' although it was unclear why Ng had become so angry. He jailed Ng for four years for rape and two years for blackmail, to run concurrently. The five outstanding charges were left on file. after the prosecution accepted the pleas.