JUSTICE is traditionally portrayed as blind but there are times when she has to be deaf as well. Mr Justice Sears yesterday overturned a conviction against Ko Yiu-chun on the grounds that a magistrate had been wrong to infer guilt from her decision to remain silent. She had been convicted of helping an illegal immigrant stay in Hong Kong, sentenced to 15 months imprisonment and refused bail pending appeal. Until recently this judgment would not have aroused comment. Mr Justice Sears was reaffirming the Common Law right to silence. He was upholding the law as it stands. The magistrate had been wrong in law. However, in the wake of the controversy over Mr Justice Macdougall's call for an end to a defendant's right to silence in criminal trials and of recent changes in the law in England, the decision carries more than usual significance. The legal profession, no less than the judiciary itself, is sharply divided over the wisdom of altering what has long been seen as a fundamental right in Common Law jurisdictions. Under the International Covenant on Civil and Political Rights, as under the Hong Kong Bill of Rights, anyone charged with a criminal offence is presumed innocent until proved guilty and may not be forced to testify against himself or to confess guilt. It is widely held that if a judge or jury may infer guilt from a defendant's refusal to testify or make a statement to the police, those internationally protected rights may be undermined. Yet limits to the right to silence are established in both English and in Hong Kong law. The Organised and Serious Crimes Ordinance already allows the police to apply to a High Court judge for permission to interview without the right to silence. The Independent Commission Against Corruption has even stronger powers. In Britain, the Criminal Justice Act has since 1988 obliged suspects to answer questions put by the Serious Fraud Squad and the Companies Act can be used to force suspects to surrender evidence. The law has recently been changed, amid enormous controversy and public demonstrations, to allow adverse inferences at trial from a refusal to answer questions by the police. These changes have been thought necessary to ensure the guilty are brought to justice. In Britain, unlike Hong Kong, evidence is systematically taken on video and strict police codes of practice protect suspects during questioning. Yet even the British Companies Act has been challenged in the European Court of Human Rights - and may eventually have to be changed. More importantly, Chinese law does not recognise the right to silence and many lawyers fear a change in the law could be abused in the future. The jury is still out on the right to silence. But Mr Justice Sears may not have had the last word.