Hong Kong's highest court has upheld a ruling that the government had warned could open the floodgates to tens of thousands of appeals by convicted drug offenders. The Court of Final Appeal ruled unanimously yesterday that the Court of Appeal was correct when it said two pieces of law had been wrongly interpreted so as to violate the presumption of innocence, which lies at the heart of the city's criminal justice system. One result of the ruling is that suspects found in possession of dangerous drugs who claim they did not know they had them, will no longer have to prove their lack of knowledge in court. It will instead be for the prosecution to prove the defendants knew about the drugs. The decision has retrospective effect and could lead to appeals from people who have already been convicted in such cases. But a senior lawyer said a flood of appeals was unlikely. The top court's decision changes the interpretations of section 47 of the Dangerous Drugs Ordinance and section 20 of the Firearms and Ammunition Ordinance to ones consistent with the presumption of innocence as protected by Article 87 of the Basic Law and Article 11 of the Hong Kong Bill of Rights. Before the Court of Appeal's decision on June 23 last year, the interpretation of the two sections placed the burden on defendants to show that on the balance of probabilities they did not know they were carrying drugs. In the case of imitation firearms, they had to show a legitimate reason for carrying them. But the top court found a reading of the law that produced such a 'reverse' burden of proof was unsupportable. It said the law should be read so that defendants need only satisfy the court that, based on the evidence, there is a doubt about their guilt. 'So read, each [provision] leaves the defendants with what the presumption of innocence exists to provide,' wrote Permanent Judge Kemal Bokhary. 'By that, I mean a measure of protection consistent with the idea that convicting the innocent is far more abhorrent than letting the guilty go free.' Concerned by the implications of the ruling's retrospective element, the government had requested that the Court of Final Appeal place a limitation on the effect of the decision by saying it would apply only to appeals active on June 23 last year or made afterward. The court decided the situation created by the ruling did not warrant such an order. The time limitations on appeals would preclude many from challenging their convictions, as would any guilty pleas. Moreover, it would only be in exceptional circumstances that a belated appeal would be heard. Senior criminal barrister Andrew Bruce SC did not envisage any floodgates being opened by the ruling, as the government had previously warned.