Judge Baltasar Garzon earlier this week broadened his arrest warrant for Pinochet, from 79 victims to cover the the killings or "disappearances" of 94 people. On Wednesday in another significant move he joined forces with a second investigating judge working on a parallel but wider case.
Human rights lawyers have been seeking to persuade Judge Garzon, to include the cases of 119 Chileans citizens who disappeared in 1974 and were never heard of again despite persistent investigation by their families. Their passports were found buried in a mass grave in the province of Salta, buried alongside other "dirty war" victims.
Judge Garzon has been investigating "Operation Condor", in which Latin American dictatorships carried out a cross-border system of military repression against dissidents. He is working with a team of lawyers to build a watertight case to justify the General's extradition to Spain to stand trial for the crimes of genocide, international terrorism and torture.
Spain's national court meets next week to decide whether or not to allow the extradition request to proceed. If it agrees, the Spanish government has said it will not object.
Spain's chief prosecutor, Eduardo Fungairino, said yesterday that he opposed the joining of the two investigations into Chilean and Argentinian human rights abuses. He also said that General Pinochet could not be charged with genocide because the victims of the Chilean dictatorship shared neither race nor religion. Spain, he concluded, would not therefore be competent to try him.
Mr Fungairino has long opposed the efforts to bring the former Chilean dictator to justice in Spain.