A HIGH Court judge yesterday upheld the individual's right to silence by quashing the conviction of a 57-year-old woman whose failure to talk to the police saw her spending 10 days in jail. Mr Justice Sears said the magistrate who found Ko Yiu-chun guilty was wrong to treat her silence as evidence of guilt. 'There is a common law right to silence. You don't have to say anything,' the judge said. He said a failure to answer police questions 'means nothing'. Ms Ko, a widowed noodle shop owner and mother of four children, was arrested after police raided her shop in Shamshuipo and found an illegal immigrant working in the kitchen. The immigrant told police Ms Ko knew she was in Hong Kong unlawfully. Ms Ko was sentenced to 15 months' imprisonment in January by magistrate Jeremy Poon for helping an illegal immigrant stay in Hong Kong, and spent 10 days in custody before being released pending her appeal. Mr Poon rejected the illegal immigrant's evidence during the trial as 'wholly unacceptable'. But he said Ms Ko's silence in the face of the allegations against her was an acceptance of guilt. Mr Justice Sears described this view as 'startling'. The decision was wrong in law, he said. The judge said the circumstances where silence could be taken as evidence suggesting guilt must be 'extremely rare and extremely exceptional'. Exceptional circumstances would apply when the failure of a defendant to give an explanation would directly bring them under suspicion. Such circumstances were not present in the case of Ms Ko, the judge said. The judge's comments come at a time of great controversy over the right of suspects to remain silent. In March another judge, Mr Justice Macdougall, called for the right to silence to be abolished in the territory. The judge, making a speech on his last day before retirement, said it was wrong to allow defendants to hide behind a wall of silence. The right is regarded by many legal experts as essential if suspects are to be presumed innocent until proven guilty, a fundamental principle of the common law system. The issue is seen as being particularly important in Hong Kong as concern over the rights of the individual increase with the approach of 1997. In allowing the appeal, Mr Justice Searssaid there was 'no doubt at all' the worker in the kitchen was an illegal immigrant. The judge warned Ms Ko that if she were caught again she would face a long prison sentence.