Baltasar Garzon, the judge who is seeking to ban the political wing of Basque separatist group ETA for five years, has a formidable reputation in Spain.

Seen as a hard-working, incorruptible and highly principled investigator, he has won respect for several high profile cases in recent years.

Most notably, he spearheaded the campaign to extradite the former Chilean military ruler, General Augusto Pinochet, from London to Spain for human rights abuses.

Although General Pinochet was eventually allowed to return to Chile, it was Judge Garzon who in October 1998 helped convince the British authorities to arrest the general in the first place.

Judge Garzon gained prominence for his actions against the semi-official (GAL) death squads which operated in Spain's Basque region in the early 1980s.

That ended with the former Socialist Interior Minister, Jose Barrionuevo, in prison.

But his impartiality is not questioned since he has also been active in Madrid's crackdown on ETA, and is reported to have been on the group's list of assassination targets.

Condor Plan

Judge Garzon has led investigations into the former dictatorships of Chile and Argentina.

In the late 1990s he started by looking into the deaths of Spaniards in Argentina during the military regime of 1976-1983.

He eventually took on the Chilean case and studied the so-called Condor Plan, a scheme by South American dictators to help each other wipe out dissent.

It was on the basis of this plan that Judge Garzon charged General Pinochet and, later, 99 Argentines, with genocide.

Political ambitions

Actions like this have put Judge Garzon on the international stage.

Judge Garzon is also known to harbour political ambitions and spent several months as a junior minister in a previous socialist government.

He walked out saying he was not being given the tools to do the job.

Party sources said he was upset about being passed over for higher posts.