Madrid (CNN) -- Spain's best-known judge was acquitted Monday of improperly investigating human rights abuses under the former dictatorship of Francisco Franco.
However, Judge Baltasar Garzon remains under suspension. He was removed from the bench by Spain's judicial authority last week following his conviction in a second case. The nation's Supreme Court said Garzon improperly ordered wiretaps while investigating a financial corruption case.
Monday's acquittal was on a 6-1 ruling, according to a court spokesman.
Earlier this month, the court dropped a third case against Garzon, saying the statute of limitations had expired on alleged abuse involving some courses he taught at New York University years ago.
Human rights groups, which sent observers to both of Garzon's trials, considered the case involving the Franco investigation to be the more important one.
"The Supreme Court has spared itself further embarrassment by rejecting these ill-advised charges," Reed Brody of Human Rights Watch said in a statement Monday. "Investigating torture and 'disappearances' cannot be considered a crime."
Garzon, 56, was suspended provisionally from the bench in 2010 while awaiting both trials. He has been working as a legal adviser outside of Spain on human rights cases and judicial issues.
Human rights groups said both cases amounted to a vendetta against Garzon, who became known internationally for his investigation into human rights abuses under former Chilean dictator Augusto Pinochet.
State prosecutors did not press charges in the case involving the Franco regime, but he was named in a private prosecution, as is allowed under Spanish law. It was led by a small civil servants union called Manos Limpias, or Clean Hands, which alleged that Garzon ignored an amnesty law approved by the Spanish Parliament in 1977.
In that case, Garzon testified that he searched but could not find any national census of how many people disappeared or their identities. He decided to investigate, he said, because he considered those to be "permanent crimes" which still affect people's descendants, since the remains have never been found.
He said he began to see evidence that there was a "systematic plan" against Franco's opponents, which he said included forced disappearances, illegal detentions and assassinations.
Franco's military uprising in 1936 triggered the three-year Spanish Civil War. The war ended when Franco's forces defeated Republican and leftist fighters. Franco's dictatorship continued until his death in 1975.
Mass graves from the regime are still being unearthed, Emilio Silva, from a group called the Association for the Recovery of Historical Memory, has said.
Garzon professed his innocence in the January trial involving the wiretaps. He ordered wiretaps against suspects who were in jail and under investigation in the case, allowing authorities to listen in on their conversations with defense attorneys and others. The lawyers later filed a lawsuit, arguing the wiretapping violated their constitutional right of attorney-client privilege.
Garzon said the wiretap orders were backed by state prosecutors, who did not bring charges against him. He testified that he ordered the wiretaps on suspicion that the suspects in the case were involved in money laundering while they were in preventative prison.
But, the Supreme Court judges wrote, "The central question to be resolved in this case is related to the fundamental right of defense for the suspect, against the legitimate interest of the State to pursue crimes. It is not possible to have a just process if the right of defense is essentially eliminated."
The court suspended Garzon from the bench for 11 years following his conviction.
Garzon said that he "rejects" the sentence and that the court convicted him in "an unjust and predetermined manner." He vowed to appeal.