A landmark challenge to Hong Kong's ability to extradite fugitives to the US is to be the subject of a full court battle with the Government, a judge ruled yesterday. Mr Justice Frank Stock postponed a bid to secure the release of Peter Chong Bing-keung, 56 - who is fighting moves to send him back to America - so the Commissioner of Correctional Services and the US Government can be represented. Chong, wanted in the US for alleged conspiracy to murder, arson, criminal intimidation and drug trafficking, claims there is no legal basis for extraditing him. His argument is based on a court ruling in America last month which held, in a different case, that there is no valid US extradition treaty with the SAR. According to the ruling, such agreements can only be between the US and a sovereign country and, since the handover, Hong Kong has not been such a country. There is no agreement between the US and China. Philip Dykes SC, for Chong, argued in a preliminary hearing yesterday that it would be wrong to extradite him given the current state of US law. Mr Justice Stock asked: 'Why am I concerned with US law? I am concerned with the domestic application of the Hong Kong fugitive-offenders legislation which talks about arrangements between Hong Kong and other jurisdictions, and there is such an arrangement.' Mr Dykes said the reason why the US ruling made a difference was that it could affect the rights of his client if he was returned. A wanted person might be extradited on certain charges in accordance with arrangements which are valid so far as the Hong Kong authorities are concerned. But once back in America, if the extradition was held to be invalid, the US Government could charge him with other offences which did not form part of the basis on which he was returned, Mr Dykes told the judge. 'He loses the protection of the extradition arrangements at the American end,' he said. Chong's detention in Hong Kong must be analysed in the context of what would happen to him if he were ordered to go back, the judge was told. Mr Justice Stock adjourned the Court of First Instance case so that the proceedings could be drawn to the attention of the SAR and US governments. Chong failed last week to persuade the Court of Appeal that the case against him was so weak he should not be extradited.