A Chilean judge has charged six people over the death of the country's ex-President, Eduardo Frei Montalva in 1982. The judge said there was now evidence that Mr Frei, a vocal critic of military leader Augusto Pinochet, had been poisoned in hospital. The arrests come less than a week before Chile's Presidential election in which Mr Frei's son, Eduardo Frei Ruiz-Tagle is a leading candidate. The former President's family has argued that Montalva was murdered. Frei Montalva died after undergoing routine surgery. The six people charged in connection with the alleged killing include four doctors, two of whom were involved in the operation and two in the subsequent post mortem.<br/><br/>