A Spanish judge who gained international attention by pursuing former Chilean dictator Augusto Pinochet went on trial Tuesday, accused of abuse of power in an illegal wiretapping case.

Judge Baltasar Garzon appeared in the Supreme Court in Madrid in one of three cases which his defenders say are politically motivated bids to stop him prosecuting crimes dating from the dictatorship of Francisco Franco.

Garzon is alleged to have ordered illegal wiretaps in a corruption case involving members of the conservative Popular Party, which returned to power in Spain last month.

Garzon "tried to intercept communications of the lawyers with the inmates Francisco Correa and Pablo Crespo," two of the suspects in the corruption investigation, a court official said, reading out the charges.

They accuse him of recording confidential conversations they had with their lawyers in jail. Garzon argues that the wiretaps were justified since the lawyers themselves were implicated in the case.

Garzon, 56, sat in court dressed in his own black judge's robes, next to his lawyer, and listened to the charges. The accusation then began its arguments in the trial, which is due to last three days.

Garzon won international prominence in 1998 by ordering the extradition of Pinochet from Britain for alleged atrocities during Chile's dictatorship. He has also pursued members of the former dictatorship in Argentina.

If convicted in the current trial, Garzon would not go to prison but could be suspended from the legal profession for 17 years.

In a second case opening January 24 he is prosecuted for ordering an investigation into the disappearance of tens of thousands of people during Spain's 1936-39 civil war and Franco's subsequent dictatorship.

Garzon is charged with exceeding his powers on the grounds that the alleged crimes were covered by an amnesty agreed after Franco's death. Garzon argued that the acts were crimes against humanity and not subject to the amnesty.

In a third trial, for which the date has not yet been set, the judge -- who has been suspended since May 2010 -- is accused of taking bribes over payments he allegedly received for seminars in New York.

In that case, Spain's biggest bank Santander allegedly made indirect payments to Garzon for the seminars and the judge later shelved a tax lawsuit against the bank.

Arriving at court on Tuesday, Garzon smiled as he was applauded by a small crowd of supporters who were held back behind a police line.

"They are covering up their crimes by going after Garzon," read one of the signs held by protesters.

Garzon's supporters argue the cases against him are a politically motivated attempt to stop the judge probing into abuses during Franco's regime, still a divisive subject more than 35 years after the dictator's death.

Among the protesters outside the court was Gaspar Llamazares, a prominent member of parliament for the left-wing IU party.

"We are faced with an act that shames Spanish democracy, justice and the Supreme Court itself -- judging an innocent person for trying to judge Francoism and also for trying to fight corruption," Llamazares said.

"I think the damage is done and the sentence is predetermined."

"I don't know the law, but I can see there is an injustice," said another protestor, Angel Fernandez, 68.

"I can see there is absolute corruption and that they are not judging those who should be judged."