It was the first conviction since 1980s amnesty laws protecting former military and police officials accused of dictatorship-era atrocities were overturned last year by the Supreme Court.

A federal tribunal in Buenos Aires convicted former officer Julio Simon of the torture and "illegal privation" of liberty of Chilean Jose Poblete and his Argentine wife, Gertrudis Hlaczik, as well having taken away their daughter, who at the time was 8 months old, a court statement said.

Human rights groups hailed the ruling as a victory, saying it marked a step toward obtaining justice after the 1976-83 dictatorship.

Argentina's military rulers seized power on March 24, 1976, beginning seven years of rule in which prosecutors say they waged a systematic crackdown on dissidents known as the "Dirty War." An official report said some 13,000 people disappeared during that period while human rights groups put the figure at around 30,000.

In June 2005, Argentina's Supreme Court struck down sweeping amnesty laws passed in the 1980s that shielded hundreds of former officers from prosecution for disappearances arising from the junta era. The ruling came after the center-left government of President Nestor Kirchner, who took power in 2003, made human rights a priority.

Poblete had arrived in Argentina in 1971 after losing both legs in a train accident in his native Chile. In Buenos Aires, authorities said he was active in a leftist group and met his wife, a psychology student. The couple had a daughter in March 1978, and were captured eight months later.

Prosecutors said Poblete and his wife were apparently taken to a clandestine torture center called "El Olimpo" and never seen again. A human rights group, Grandmothers of the Plaza de Mayo, said the couple's daughter was handed over to a military officer's family and her identity was re-established in 1998.

The trial began June 28 under heavy security as authorities called more than 30 witnesses who gave gripping accounts of torture and accused Simon of being involved.

Simon waived an opportunity to speak before the verdict and sentence. Defense lawyers argued there was insufficient evidence to convict him, and vowed to appeal.

Estela de Carlotto, president of the Grandmothers of the Plaza, rejoiced at Simon's 25-year sentence, saying, "this is a big day on the path for all the trials" in the future.

Poblete's stepbrother, Fernando Navarro, told reporters, "I can't express my joy."

The 2005 overturning of amnesty laws has raised the possibility that scores of former officers could be called back to testify or eventually face prosecution.

Also in June, a 76-year-old former police investigator, Miguel Osvaldo Etchecolatz, went on federal trial in La Plata, 35 miles southeast of Buenos Aires, on charges of ties to the kidnapping, torture and disappearance of five people under military rule. That trial is ongoing.