Stunned rights activists erupted in protest Thursday after Spain's Supreme Court convicted a top judge renowned worldwide for defending human rights.

Many fumed at the court's unanimous finding that Baltasar Garzon was guilty of ordering illegal recordings of suspects talking to their lawyers in a corruption case that implicated senior politicians.

No-one accused in that case has been convicted.

But the 56-year-old was barred for 11 years from being a judge or magistrate and fined, effectively ending his once-soaring legal career. He can still take the case to the Constitutional Court.

Justice Minister Alberto Ruiz-Gallardon said the right-leaning Popular Party government had "the utmost respect for the decisions taken by the magistrates in this case".

The head of the Madrid regional government, Esperanza Aguirre, also of the Popular Party, went further.

"It is a happy day for Spain and democracy," she said.

"You know why? Because the ends -- and I have no doubt that Garzon's ends were praiseworthy -- the ends cannot justify the means and that is the basis of the rule of law."

About 500-600 protesters rallied in Madrid's central Puerta del Sol square chanting "Shame", and "Garzon, friend, the people are with you!" They brandished banners reading: "Justice!" and "We need more judges like Garzon!"

"What they are doing with Garzon is shameful," said one demonstrator, Albino Calva, 75.

The judge's daughter Maria Garzon issued an emotional written defence of her father, who earned worldwide renown when he tried to extradite Chile's former dictator Augusto Pinochet from London in 1998.

"To all you who are today toasting his suspension with champagne... to all you who for years have made insults and lies... I say you will never make us bow our heads," the daughter wrote.

"You have hit us but not sunk us, and far from making us lose faith in this society you have given us more strength to keep fighting for a world in which justice is genuine."

Besides the conviction for his probe into the corruption case, which implicated some Popular Party members, Garzon is awaiting a verdict on charges of abuse of power for investigating Franco era atrocities despite an amnesty.

"It looks like Garzon's enemies got what they wanted, which was to cut him down to size," said Reed Brody, legal advisor to Human Rights Watch.

"Absent the most compelling circumstances, the prosecution of a judge for a judicial action constitutes a threat to the independence of the judiciary," he told AFP.

"The result of such prosecutions is to create judges who are subservient, which is not what a democracy needs."

Pedro Nikken, president of the International Commission of Jurists, said the combination of cases against Garzon made it look as if there was a campaign against him.

"The circumstances of this sentence cannot avoid being seen internationally as a punishment of the judge Garzon for carrying on investigating the Franco-era crimes," Nikken told AFP.

Ordinary Spaniards expressed suspicion over the cases against Garzon and the conviction.

"He is the best judge Spain has had," said Emilio Garrido, 87, a passer-by in a Madrid street. "Now he has opposed the government that we have... this is what he gets."

"It seems to me like the world is back-to-front," said another, Begona Antonio, 55.

"The judicial system is bad in Spain. There are the remains of Francoism. It is a shame and makes me very sad."