London - Lawyers for Chile and its former dictator Gen Augusto Pinochet argued yesterday that the international Convention against Torture came into force too late, and was not specific enough, to allow Spain to prosecute him for the crime. They were addressing Britain's law lords in a rehearing on whether Gen Pinochet has immunity from prosecution for torture, murder and hostage-taking as a former head of state. Mr Clive Nicholls, for Gen Pinochet, said that of the 30 charges made against him by Spain, only one involved torture committed after 1988, when Chile signed the convention.